Interesting... This seems like exactly what I want:
[quote]Digital Fuel Adjuster
Ref: High Performance Electronic Project for Cars – Silicon Chip Publications.
This unit is a huge revolution in DIY automotive performance. It gives you the power to completely tune the air/fuel ratio throughout the entire load range, at 128 load points, providing incredible mapping resolution and brilliant drivability. It uses the Handheld Digital Controller – KC5386, so there is no need for a laptop, and it supports both static and real-time mapping. It can be used on 0-5V and 0-12V signals, so it is compatible with all voltage output airflow meters and MAP sensors. It can also be set to work with 0-1V signals, allowing modification of EGO sensor signals. This unit has been extensively tested on a wide range of cars including Subaru Impreza WRX and STi, Nissan 200SX, BMW 735i, Lexus LS400, and Nissan Maxima. Kit supplied with PCB, machined case, and all electronic components. Kit requires the Handheld Digital Controller – KC5386.
[/quote]
I have been using the unit now for the past four week. I originally bought the unit to use on the MAP sensor of my Subaru 2.5 Auto liberty to reduce the fuel usage a bit. Started down the HHO path and simply did not get around to building it.
Finally I put it together and fitted it up to control the Ehaust Sensor. With the HHO alone I was able to reduce the fuel consumption from around 9.3 litres per 100 k's to 8.5 then finally i fitted up the digital fuel controller and i am running 7.9 to 8.1 per hundred.
For the last 1000k's I have had the HHO turned off and I am returning 8.5 per hunred, that was really impressive.
What I like about the Digift fuel Adjuster is the ability to totally control what you are trying to control. For example I need to add 0.2volts to the exhaust sensor out put, but i only want to add the volts at a 0.3 to 0.8 volt range. To easy and it can be done on the fly while diving up the highway, no need to stop.
I have now bought a second unit that i will be adding to control the MAP sensor. It will take a while for me to get around to fitting it but I am really looking forward to seeing the next level of improvement.
Very interesting. To me this sounds like a very good solution. Not as involved as going standalone like a megasquirt or getting into custom cals. Do you have any gauges? EGT or wideband A/F to help tune it?
[quote]I have now bought a second unit that i will be adding to control the MAP sensor. It will take a while for me to get around to fitting it but I am really looking forward to seeing the next level of improvement.[/quote]
Why a second unit?
does one unit only control one sensor?
Yes you are right, one device - one unit. The Digital Fuel Adjuster can only accept one input. Though at $79 and about 90minutes to construct it is still pretty good value.
To use the Digital Fuel Adjuster you will need to have a Hand controller, also $79 and a serial cable to link the two together, then the adjustment is easy.
For assistance with tuning I have a couple of good friends that are mechanics so i can have the results checked. The changes I am making are really slight as I am trying to stay on the safe side. My car is used for work and I travel approx 200 k's per day. So in a few days I have a good idea of what worked and what failed.
My apologies for the last reply, i made a number of spelling mistakes I missed in the rush. Hope this one is a little better.
I originally set the car up with another JayCar kit to monitor the A/F. Just the basic kit that enables you to set up to monitor closed and open loop running and a couple warning LED for ratios above 16:1. Of course all this was done with the assist from a mechanic to check. On running the car, the first map I ran caused the car to ping, five minutes later I retuned it. I had made a mistake with the setup, got it close the second time, third time is better again.
The basic setup allows 128 point changes per volt range, for me I am monitoring 0 to 1 volt of Exhaust Sensor, with 128 adjustments in between. I add 0.2 volts to the 0.4 to 0.8 volts and bleed the volts to zero change on each side of the change. The car runs so much smoother under the current config. With the HHO cell in conjunction at a minor 0.5lt per minute the car handles long hill runs without down changing from over drive.
Subaru’s run rich most of the time, so there is some room to move. I leave alone full rich, I leave alone full lean, as I do a lot of 130k of high 110kph driving on the flat and on cruise control it works best. I then spend two hour a day stuck in traffic. What I have found is that for me, saving fuel at idol and getting up to speed is where it needs to be. The highway run is really economical, it’s the stop and start in Sydney traffic that is the killer, it’s only 55k’s of city driving but the average speed for Sydney these days is 22kph due to the traffic.
Hi,
those are impressive figures for a 2.5L Subaru. What year is it and does it have auto or manual trans? I am just running a custom Efie for the O2 sensor and a voltage adjustable MAP modified signal and I have gone from about 8km/l to around 9.5 km/l mostly urban running with an MY2000 auto 2.5 Heritage wagon.
I will be going on a long trip early June with lots of previous km/l readings so that ought to be interesting! I'm also based in Sydney so perhaps we can catch up and compare notes on what does and does not work.
Good to hear that someone else is playing the Subaru game for economy, most go for HP. My car is a Aug 1999 Subaru Liberty Heritage sedan with the four speed Auto. Wheels are 18 inch with 215 x 35, the rolling diameter is the same as standard. I have to say the low profile tyres help with consistency, I run 55psi, the change in tyre pressure makes little difference with such small side walls.
Under the bonnet the car is mainly standard, well maintained at the Subaru recommended intervals. I run a K&N panel filter and slightly colder NGK plug to help with the pinging factor if it occurs. Finally I have JayCar Digital Fuel Adjuster on the O2 sensor.
The daily drive is South of Wollongong to Rosebery, 5:45 am leave time in the morning and 4:05pm in the arvo back home 95k’s each way, I do the speed limit everywhere, I don’t see the need to rush. I try to fill up at the Ampol at Kirrawee at the same pump on the way home for consistency. Let me say though, I have filled up in Wollongong and found some really funny fill readings. Dare I say there appears to be some pump cheating going on. I have also had a good friend go to a station with a ten litre drum for their race bikes, the pump says ten litres but only nine is in the drum, so I avoid those stations now.
OK back on the topic, I have not had the chance to get the MaP sensor side running yet, hopefully in the next month. This weekend I hope to add the new Browns Gas Booster I have been working on. For me it is exactly that, a booster to help the octane, never any more than about 0.5lt per minute of gas has given me the best results. So next week I should have more figures to go off.
By all means I would be happy to have chat, you can contact me by email at john@factoryelement.com that is my home email address. Over the next month I will be changing our website to be a factual site around MPG, petrol prices right now are stupid. So any help we can put together for the battling Aussies out there the better. I fill up twice a week at $75 a pop, it’s nuts.
I am interested in hearing about how you have set up the MAP sensor as that is the next project. I look forward to hearing from you soon.
my Subie is a mid MY2000 2.5L auto Heritage Wagon (heaviest Lib at the time). I used to get abysmal fuel economy when I first bought the car (preloved) 1st owner used to get 350km a tank commuting and 550kms on long trips; not exactly good. I'm up to around 9 - 9.5 km/l commuting (not stop/start). That used to be the avg km/l for a trip up the central coast from the Hills district. I expect better now. Best was about 12km/l on a Canberra trip driver only on the speed limit and again I expect better. I suspect this car came standard with slightly retarded timing as the original performance was pretty dozy.
I've got a complete MRT extractors, high flow cat and exhaust fitted (long story how that came about but not looking for performance) but got it anyway AND better fuel economy.
I've tried lots of things, still using additives, mainly acetone, xylene and napthtalene for about a year now with no bad results except for having to clean the fuel pump filter from brown gunk 3 months in. It gets me about an extra 10%. The MAP modification is the Jeep 5V regulated one, currently running at 4.5V. Incidentally the orig Subaru voltage was 5.12V in one car and 5.16V in another (Outback) Seems the ECU runs a little higher to get aroud poss voltage drops. I also run an EFIE set very aggressively- get the occasional CEL but no probs.
IAT resisters no good. CAI no good, HAI no good, fuel heater no good and PCV jar and atomiser not great but runs a cleaner engine. However this was all trialled before the EFIE so I'll have to do it all again.I've also used Boric acid in the engine oil and through the intake manifold. Bought a Scangauge II to speed up testing but it doesn't work with this model!@#$%^.
I am toying with the idea of using the digital fuel adjuster combined with a wideband O2 sensor as it would give me great readings on AFR while keeping the ECU happy!
I have also to fit an HHO generator but car has to back to MRT for a "tricky bits" dyno tune they still owe me so I need to have the car pretty much standard. I'll be interested in your results with it. That would bring it close to the HAFC setup for a 2.5 Auto except for the fuel heater/ionizer , they claim 60mpg for a 2.5L auto on the highway, that is a 65% improvement on 12.5 km/l EPA.
Best results with MAP and EFIE combeine are only recent BUT repeatable!
Sorry about the delay in getting back to you. I took the time out to go back over my own result and see what worked and what has not. I found that a HHO cell worked well, the simple reliability of the device being the biggest issue. After six month use at 3.5 hours per day of driving the cells would be burnt out around the positive terminal and basically fell apart.
Once I had added the Digital Fuel Adjuster I found that my result started to become steady and did not vary a great deal. I don’t know that a wide band O2 sensor would be worth the effort. My setup gives 128 points to modify in a one volt range. I found the first setup that was aggressively setup did not work. My next config was more sensible and mathematically better.
I set it up by dividing the 0-1.0volt by 128 point, that meant that a 0.2volt setting was 27 points on the hand controller. I then looked at what I wanted to achieve. Light to mid throttle change, so 0.4 to 0.8 volt range and added the 27 points to those then 0.1 volt either side I tapered the added volts to zero add. This gave immediate result. It also meant the car stayed within normal full lean and full rich ability. The car runs really well at this range and the base line fuel consumption was now down to 8.4lts per 100 combined City/Hwy.
In the last two weeks I have been using a Novak vapour device. Interesting that I am now seeing 8.1lts combine average, very surprising as the only vacuum line I could use draws no air at idle, only above ¼ throttle would create enough vacuum to draw air through the Novak unit.
I take a very simplistic approach, keep it as close to standard and build from there, one change at a time. I believe every car has the ability to run more efficiently as the manufacturers run them all really rich to make them last through the warrantee period without any needed work. If it was a high end sports car, then they are tuned to go and go hard. The Liberty is a classic small engine heavy car setup so I view it like a taxi. Designed to last and built tough, so there is room to improve.
Really the big thing is knowing where you are starting from and understanding how it works. That can be really hard sometimes. My first mod was a JayCar Fuel Mixture Display, $15, 30 minutes to build and 60 minutes to fit. What this shows is the closed loop / open loop points in my driving style and I adjusted to suit. Then I had the car running as economical as possible before changing anything. That gave me an average of around 9lt / 100 combined running really easy on the throttle. Now my result are better and I am driving harder than I did when setting the base line.
I still haven’t had the time to look at the MAP sensor, three kids is a killer to play time on the car. But I am happy to live with the delays, I am dad first. I have had the performance cars so that is out of my system for now.
My next step will be the new HHO followed by the MAP sensor Digital Fuel Adjuster mod.
John, have you considered disabling the oxygen sensor (either by disconnecting or supplying a fake signal) and using the DFA to completely tune your car in open loop?
As a keen reader of autospeed myself, I noticed that when the Maxima (one test car for the DFA) was stopped for a roadside emissions check, it was well within spec. With a large air-flow meter bypass, intercooler, modified exhaust, an a disconnected oxygen sensor.
Maybe you should consider doing that instead? Closed loop wouldn't exist, but then you wouldn't exactly need it either (at least while all of your sensors are working fine anyway).
Autospeed has really interesting reading and some great approaches to problems.
I have thought about removing the O2 sensor from the equation. But have put it further down the list. My thought is that it is there for a reason. Seeing as I am trying to improve what is already on the car and don’t intend on changing to far from that the O2 sensor would be a few steps away.
From memory AutoSpeed had an article where they turned off the O2 sensor on a Prius for particular load readings, I will need to go back and find that article later.
I guess my concern is that removing the O2 sensor would drop the car into an error mode and ultimately have the car run full rich all of the time. That in effect will be worse for economy. I found when the DFA was setup aggressively on the O2 sensor my fuel consumption increased, the new setting have move the reading a little off what the ECU expecting from the O2 sensor and the consumption is really good.
One of the things that is really annoying with the Liberty is the ability to find any one that can tune it for economy, everyone I rang said no, but we can make it go harder. The guys at MRT where the same, basically the response was, not worth the effort to write a program to do that. Maybe at $1.60 plus a litre more people will ask and someone will eventually go sure thing.
Do you remember what wire of the standard Liberty MAP sensor was sending the voltage signal to the ECU?
If you have a multi-meter it isn't hard to find. On my Legacy GT (Liberty RS) it only had three wires going to it. One was constant 5v, one was earth, and the other is the signal (varies between 0 and 5v, depending on manifold pressure)
Don't the normally aspirated engines have an air-flow meter?
Sorry about that last reply, i thought you where another Forum user I had been talking with.
I believe it is a MAP or MAF, I have not taken to hard a look at this stage. From memory it is a three wire unit so I will run the Multimeter over it. It is certainly different to the older Liberty and not the same as the WRX my wife had previously.
I will take a look under the bonnet tonight and check it out.
I figured that, that's why I left my name at the bottom.
Well my GT was a 1990 model with an airflow meter, which is very similar (if not identical) to the early WRX setups. If it only has three wires, and is only connected by a vacuum line, it's a MAP sensor.
My car had both (MAP and MAF), the MAP sensor was primarily used for the fuel cut (overboost protection), and when an obvious fault (ie no connection) with the air-flow meter occurred. Without the turbo, however, your setup is not going to be like mine.
Incedentally, the oxygen sensors would be primarily there to make sure a one-size-fits-all program actually does fit all the cars for the warranty period (and longer). If you are monitoring the output of the oxygen sensor yourself (as a rough guide to rich/lean) and have the ability to tune the car yourself (through the DFA), I see no real reason for keeping closed loop. Especially if you are like me and can't resist pressing the buttons every few days in search of that elusive sweet spot.
Does your car have some kind of distributor? If it does, the new programmable ignition (the one that uses the hand controller) from silicon chip might be something for you. That, with the DFA, would allow you to have a completely programmable fuel/ignition system. Allowing you to take advantage of any combustion enhancing device you may fit.
I know where you are coming from and being in IT you tend to look at the electronics first.
it is definitely a MAP sensor. I also had a 92 wagon that ran on LPG for a number of years. Easy enough to do, even though Subaru say you shouldn't and you can't. 400000k's later the only thing that killed was the idiot that pulled out in front of me. That thing was a rocket on gas, but, 13+lts per 100. Makes the current car at 8 to the 100 nearly the same price to run.
I had a look at Silicon Chip Engine Management, just to much trouble for the amount of time I have free. I will definitely look at going without the O2 sensor. I could in effect use one DFA to intercept and the other to remap the MAP sensor.
I'm not exactly sure what you mean by using two DFA's on the same sensor there...
Although with the MAP sensor being a vacuum operated potentiometer, you can do various things to the input voltage as well.
Remember that the problem with intercepting a MAP sensor is that the signal is altered by the same amount at all load sites.
You could try when you have a DFA on the MAP sensor is to disconnect and plug the vacuum line to the fuel pressure regulator. At low loads this will raise the fuel pressure by 10 psi, tapering off to zero at high loads (21 inches of mercury is maximum vacuum on decel for my GT. It idles at 18, and cruises at 14. Disconnecting that line would raise fuel pressure by 10.3, 8.8, and 6.8 psi respectively under those conditions). You can correct for this with the DFA on the MAP sensor. The theory is that higher pressures and lower pulsewidth delivers the same amount of fuel through the same injectors, but with a better (finer and more consistant) spray pattern, for better vaporisation. At high loads it will be stock fuel pressure.
All of this I would do on my current car (an EF Falcon) if it had a voltage outputting load sensor. All I have to (not play with :( ) is a frequency outputting MAP sensor. Worst of both worlds...
Quite a mixup in posts! Never mind, the early Liberty's (nee Legacy) with the quad cam motor ran MAF sensors. The SOHC 2.5 have a combined MAP and IAT device mounted on the manifold. In Australia it is available on RX and Heritage from late 1999 onwards. Don't know off hand which wire is the 5V return. Bear in mind that I tapped into the 5V ECU supply side and varied that down in order to get advanced timing and leaner mixtures. The reduced 5V supply also affects the IAT output, making the ECU think that it is hotter. It may also retard the ignition but I think the MAP sensor overwrites that.
I got to build that Jaycar AFR meter and see what the mixtures are doing, I'm using the LED mixture meter since about 1995. It keeps me entertained! What HHO generator do you have and what gas volume are you aiming for? I know exactly where to put the gas, the vacuum port you describe is the one I use for upper cylinder cleaning and also water/metho mixture (metered) to help cleanup any carbon deposits. I don't use it all the time just prior to every 25,000 km service. I've also read up on dual entry for the gas, one after the throttle body for light throttle and one before for WOT.
I'll pull the MAP sensor in daylight and let you know the wiring colors.
Ben, I am looking at running the Current DFA on the O2 Sensor and the second on the MAP sensor, but I really am going to think about the operation after your findings. The DFA can be set to any load at any range based around the 5V out put, even off setting it slightly may make a difference. Food for thought I guess.
John N, My car is August 1999 so it is probably going to be one or the other. Where is the IAT device located?
On the HHO front, it is on the bench at the moment. I have lathed up some nylon ends, I run a small plate size. 150mm x 30mm in a Pos/neg with five sets at 1mm gap. I am building this currently and will get it together over the next few days if time permits. Once together I will email you some photos. The aim short term is one litre per minute at 10 to 15 amp. Once up and running I am going to build a second unit and daisy chain them so one feeds the other.
The old one was similar, put had 7 plates and ran just under one litre per minute at 20 amps. It simply fell apart, to much current, to much heat. I have cut this one up to take photos
Gas input is through the main inlet for the throttle body. Have a look at you tube, I believe that ZeroFossilFuels had an article on it.
The IAT and Map sensor combined unit on my Sub (feb 2000) is located to the right of the igniter module,the 4 legged spider thing that the spark plug leads come out of. I think it is a 4 lead plug connector. If you cannot locate it your car may be running a MAF sensor which would be located in the tube before the aircleaner box. I'm pretty sure your model (Gen3) should have the combined map/IAT sender.
I have modified the EFIE to activate and simulate the waveform at a super low 50 - 100mV after looking at the O2 sensor output curve. Because of the steepness of the curve around stoich a 200mV trigger point would only yield about 15 to 1 whereas a 50mV trigger would yield aroud 16 to 1. I can easily run that ratio given acetone/xylene additive mix and the fact that Subies tend to run rich anyway. There is no noticable effect on drivability, if anything the car steps off better!
Leaning out is confirmed by the Led O2 indicator kit, it is spending much more time in the lean rather than average setting. Sometimes it shows no reading at all for a time then starts up again. At higher settings there is not much difference to standard.
Thanks for that, Yes mine is the same. I wasn’t too sure what the IAT was as I appear to have a device on the right hand side of the throttle body, looking the car from the grill. I thought that may have been a throttle position sensor. But I really need to get under the bonnet of the next few days. Time just has not permitted any fun activities of late.
When the O2 sensor is showing no reading the car is in either full lean off throttle mode, or relying only on the MAP sensor output for fuel requirements. Speaking with a friend that does a lot of ECU mods out of their work shop ( mainly for performance, they do a lot of super street drag cars ), he recommended always down changing to third when rolling down hills or to a stop as it forces the ECU to shut down the injector in these conditions. If I employ that tactic I have found that I regularly hit the 8.0 Lt/100k range. Yeah I do a large down the mountain run into Wollongong.
I will do some research into the other box and see what I can finds out.
the device just to the right of the throttle body is indeed the throttle position sensor. The MAP/IAT sensor is directly to the right of the igniter further towards the front of the car. To gain easier access it is helpful to disconnect the #4 cylinder spark plug lead at the igniter. Furthest towards the rear and on the right.
I think there are 4 leads, 5V ecu out (mine measured 5.11V) IAT out (this varies with air temp) MAP out (this varies when you idle and blip the throttle) and the 4th ????(earth?? ) I cut the 5V ECU out wire and substituted the ajustable voltage regulator. This affects both the MAP and IAT outputs of course and there will be a point where the perceived higher air temp will retard the ignition again although it will help to lean out the fuel mixture a little. This will not happen if you use a DFA on the MAP output end. Hope this helps.
I will set some time aside this weekend to take a good look at it all in more detail. The MAP sensor sounds like real bugger to play with. The older 2.2 Liberty I had with the Air Flow Meter which appears to sounds like it would have been a lot easier to adjust. My other thought, but I still need to research, it is to maybe adjust the out put from the TPS. The throttle position sensor has to be recording back the opening to ECU and inturn have some effect on the fuel input. I also would imagine this would be a voltage setting. I believe there maybe an article on this in the performance electronics mag from Silicon Chip.
I also hope to get 2 hours to finish off the HHO Booster this weekend, I will get some photos through to you when I am done. It feels like months now since i started on itand it is still sitting there. Bring on the long weekend.
Again, thanks for you help. It will save me a stack of time.
On most cars the TPS is only used to calculate shift points, and idle/cruise/WOT conditions. In normal driving in a manual it effectively only controls when closed loop is to be used. It is also used as a backup when the primary load sensor fails.
I re-read my previous post and realised I said something wrong. The altering the MAP sensor signal will effect the entire RPM band at once (when at that load). An example is that a MAP sensor on a naturally aspirated engine will show 5V from idle to redline if the throttle is open.
So you can lean out low loads, but ALL low load sites will be affected. However, since the engine isn't actually doing much at 4000rpm with 14 inches of vacuum, it probably doesn't matter much. Seriously, when was the last time you were two gears lower than you should be for long enough to notice a flat spot?
After 6 plus years of on/off experimentation with 5-6 different cars I'm finally getting somewhere!
In the latest car (Subaru Heritage 2.5L Auto Wagon) I have reduced fuel usage from about 7-7.5Kms/ltr to latest 9.5-9.7kms/ltr using 6week moving average results, full tank to full tank average trip around 400kms between fills. All urban running with some free flowing motorway occassionally. Best on highway now 13kms/ltr.
I use the following:
acetone,xylene, upper cyl lube and naphtalene added to fuel at fillup
Engine and fuel system Ba treated-had some filter blockage issues
EFIE (not the ER one) set to give 1V deflection at 50mv input
MAP voltage at around 4.5V instead of standard 5.11V
PCV canister with fuel bleed at max 3ltrs/hour using model airplane needle valves
Basic Hot air intake.
Next step is to complete AFR meter and install part of HAFC hho generator.
Locate and install CTS compensation, probably using thermistor and fixed resistor.
Install O2 extender if obtainable. Is there anyone willing to help me get a special Stant thermostat and the Help! 42009 spark plug non fouler from Autozone and ship to Australia at my cost please please- cannot get these items in Oz and no stockists will send O/S
I have Paypal so can easily send funds and USPS Global priority mail is pretty cheap! Just PM me....
Seeing I cannot get my scangauge II to work with this car I may buy a fuel injector duty cycle kit from Jaycar to study more immediate effects of my tinkering. A week to wait for results is a long time......
I'm told an identical car achieved over 60mpg higway in the HAFC blurb..... so there is still much work to do.
It is good to hear that you are making some head way. I also saw the HFAC guys saying they are getting 60MPG on the highway from an Auto Liberty 2.5. That’s 3.9lts per 100? Kind of depressing when you look at the target we are setting ourselves.
Looking at the result and what you are achieving, while good compared to where you where with MPG, I am left a little puzzelled. My reason for this is that currently I am only running the DFA on the O2 sensor and constantly return high 11 to mid 12 kilometers per liter with E10. No additives nothing. For example I see 610 k’s on my tank prior to the fuel light coming on, I can almost set my clock by it.
I am just wondering if something you have added is stopping you going further with the mods you currently have, is one of them maybe holding you back. It is just a thought and maybe a revisit of the mods you have made to check their effectiveness will result in a dramatic improvement.
I do have a question on the MAP sensor, the vacuum line that comes from that runs out to a small box with a power circuit. Do you have one on your car and do you know what it is called. Running a Novak Water Vapor a month or so back as a test had me wondering if that is the right place for it and what I am effecting. To date I have not been able to find out what the box is.
Yes my fuel economy is kind of depressing. When I first bought the car s/h it felt a little dozy compared to my previous RX auto (the quad cam model) but otherwise the car was in great condition. I thought it was just tuning but the previous owner said he got 350km/tank urban and 550km/tank highway. Not great. I have seen as low as 6km/ltr in stop start commuting! The mileage I am referring to is strictly urban running with stop start traffic and the occassional 80 km run. On a trip to Canberra I averaged 8.2 ltrs/100, don't know what it would do now.
I normally travel to the snow regularly but there isn't any yet this year so no long distance cruising mpg yet. Your mileage is impressive, I'm envious, however mine seems to be more in line with forum topics at Ozliberty and MRTrally.
From your description you have a different map sensor, mine is attached to the manifold with no vacuum tubes at all. Probably worth a look and compare cars sometime. Apropos the various mods I have documented what improves and doesn't improve things. There has been an occassion the car had to be bog standard and in that form it promptly dropped to 8kms/ltr where I now get around 9.5 kms/ltr.
I agree it's a long way to 3.9 ltrs/100 but that is what makes life interesting!
I was lucky with my car, an old guy owned it from new full history, nothing but Subaru servicing. Then I bought it. I just have to think that something is in the way on your car. It was poor from day one which makes me think your effort are being sabotaged by some hidden gremlin.
My driving is split 50/50 in time between HWY/City. Maybe it’s my grey hair driving style. But even nothing but city I get just under 600k’s before the light comes on. Prior to the DFA it was 520k’s HWY and the light was on. I have had a few runs lately at 130> on the freeway for 70 odd k’s, plenty of hard acceleration in traffic and still return 11k’s per litre.
My glove box manual says the car will do 6.8HWY/9.3City. So for now my target is 6.8 combined. Achievable I believe.
Just from our conversation on the forum I have some items under the bonnet that I can’t find any info on, so today I order a workshop manual from Repco. It will be interesting. I know early 1999 Gen3’s had a MAF and late 1999 Gen3 had a MAP sensor. But I am wondering if there is another in between one? The manual will give me some pointers I am sure.
I will be back on HHO after the weekend, so it will be interesting to see how it goes.
I will try and get some photos through to you soon.
I'd like to test a pair of the Digital Fuel Adjusters on my '99 F150... Are they even available in the US? I couldn't seem to find the order page. Either that, or the "out of stock" page replaces the order page. :(
In Australia they are easy to pick up generally three or four on the shelf at all times. Checking the site I would say the warehouse may be out of stock but the retail stores have them on the shelf.
You will need the DFA ( one for each sensor) plus a hand controller. If you have any issues locally I am sure I can arrange to go up get them for you and send them over. We can arrange payment through paypal and air mail with insurance with out to much effort.
HI! There, I'm new to this forum and glad to find it has lots if info, my situation is i'm in the process of buying all the parts for HHO cell on my 01 subaru forester, it has a stock 6 wire bosch 02 wideband part # 17018 on the front and from what i have read it looks like the Jaycar DFA is one my solutions to adjust my wideband , is their anyway cheaper?? I am also running a hi flo cat,do i need to do anything to the rear 02?? Also not sure what my options are for the AIT/MAP?? for parts to adjust, i do have an eagle research efie from 98 forester not sure if it can be used.?I'm also not sure the best place to connect the hho hose and i think i should have 2 different connection 1 on intake and other near throttle body intake?? thanks for any help. sorry for . many??? Brett Canada. :?: :wink:
My understanding of the Eagle Research Efie would say use it. Only the front O2 sensor will need to be monitored. It is designed to simply add a positive voltage step, so 1v or 5v should work.
Myself I am going to madify the MAP sensor with the second DFA I have pruchased. Should start the build this week.
With the HHO I run mine to the air filter side of the throttle body, through the side of the intake trumpet. Once I have ironed out the final bits and pieces sorted out I will fit a proper LPG plenium to give better results for HHO mix.
HI! John, Thanks for your help , will be a few weeks before i get all my ordered parts to gether , i can connect my efie up and my laptop with elmscan software and see how the efie will work before and after HHo install. Will probably have more questions. Will keep you guys posted .Thanks John.
After a lot of trouble getting the second DFA running on my 1999. Not to sure what was wrong with the device, I bought another unit and had it up and running in about three hours.
Any way back to it, i have added the DFA to the output signal of my Subaru MAP sensor. Set the DFA to start after the engine is running and I am now returning good milage with HHO. I am hitting 8\100.
Every other time I have run the HHO the ecomomy would go out to 8.3+\100. so this is a good starting point and I can modify the signal MAP to hopefully get deeper into the 7's per 100k's.
Hey there DFA users...
I have just built my DFA and Hand Controller unit and cant get past the first testing/calibrating step. Hoping someone has had this issue and knows a fix. I have been emailing back and forth with a guy from jaycar and it seems that I have everything built and put together properly.
When I put power (using my truck while running 13.8v) to the DFA as per the instructions, I get a quick flash from the LED and hear a click which I assume is the relay. There is 13 volts going in and I am reading 2.25v on TP2. SCR1 shows almost 1 volt which I am told it should. There is no power going to the hand controller (it has the correct cable).
The pot VR4 that adjust the turn on power seems to have no affect when turned either way.
???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
I hope you all can help... [-o< [-o< [-o< [-o<
Thanks
I have built three of these units now. The second one is on the shelf in the shed, could never get to run, checked checked and checked again, change all major components, many hours and days waisted. Same thing the RED LED would flash then go out. I ended out buying a third unit which was up an running with in three hours. I am wondering if there is a batch of them that is dud.
I have not had the time to finally sit down and work out the difference between the three units, I did notice that one of the parts was different the BC327 in the two units that do work was on a card board strip with the pins straight not stepped. I have not gone back to JayCar to pick up a replacement part.
The LED must stay on for the unit to work.
If the LED is staying on, the hand controller must be attached prior to powering on the DFA. If that is the case hand contoller attached, DFA powered on and the LED is on. But the hand controller is not lighting up, then you need to adjust the trimpot in the hand controller, it controls the brightness of the display, from out to on. That one took me a while first time out.
Let me know if either of those is the issue and I will compare mine for you.
Ok final I have the answer to why the second DFA I had was not working. Seriously I can't believe it. I have change all major components. Still no good, finally I had an hour free and caught the manager of my local JayCar store. Asked if he could check it for me.
Ten minutes later he turned and said the 330r and 330k resistors are in the wrong spot. We changed them around and bingo, it works.
The pain I went through,I simply could not see it to save my life.
So to Chris the manager of the Wollongong JayCar store, THANK YOU!!
[quote="Atechguy"]HI! There, I'm new to this forum and glad to find it has lots if info, my situation is i'm in the process of buying all the parts for HHO cell on my 01 subaru forester, it has a stock 6 wire bosch 02 wideband part # 17018 on the front and from what i have read it looks like the Jaycar DFA is one my solutions to adjust my wideband , is their anyway cheaper?? I am also running a hi flo cat,do i need to do anything to the rear 02?? Also not sure what my options are for the AIT/MAP?? for parts to adjust, i do have an eagle research efie from 98 forester not sure if it can be used.?I'm also not sure the best place to connect the hho hose and i think i should have 2 different connection 1 on intake and other near throttle body intake?? thanks for any help. sorry for . many??? Brett Canada. :?: :wink:[/quote]
Brett, My experience with the 6-wire O2s is that the EFIE cannot possibly work. I got best results by putting resistance in the signal wire. On the Kia I tuned it ended up being 180 ohms. Hope that helps.
you asked____ I do have a question on the MAP sensor, the vacuum line that comes from that runs out to a small box with a power circuit. Do you have one on your car and do you know what it is called. Running a Novak Water Vapor a month or so back as a test had me wondering if that is the right place for it and what I am effecting. To date I have not been able to find out what the box is.
John Velo
Factory Element
Answer_-- If you are looking form the front of the motor (I have an 01forrerster 2.5L) the thing you spoke of runs out towards you and has a thermistor and vacuum line attached! THAt is the Idle air control Valve___I would mess with it...that little jewel keeps your car from surging at idle or at least I beleive that is what is does...none the less it is the idle air control valve...
***I have been all over the web looking for the answers to beat my Suby so I can get my HHO running___and would like to say thanks for all of the info :lol:
Another note as far as that little water vapor cannister mentioned here! I also have TWO Pond Foggers set-up that are ni my car ready to go____going to try cool distiled water/alcohol vapor first with the NEWLY discovered answers I found here as far as my electronics go! check out foggers on youtube! I got mine off of Ebay...the thread was actually found on another fuel saving sit. simple to install the ones I got do 300ml on 24v's at 1200ma...got a 400 watt inverter so I can run both! Stuck them in an ABS can just like i would a HHO gen....ran a plastic fuel filter on the vent to introduce air into the can then hooked a PCV cleanng can and plugged my intake into it! SO my cool water/alcohol vapor will be sucked into the vacuum side in between the engine block and intake through the PCV loop.... going to run 91% alcohol at around 50/50 distilled
Hey guys just to let you know. If you do not want the trouble of assembling the Jaycar DFAS. Silicon Chip Magazine and JayCar have allowed Punk_Performance to do a commercial version of their DFA unit. well priced at $299.99 and a bit more stylish. All units are checked and tested before post. They are on the Punk_performance website as well as listed on eBay if you want to sought through those dodgy chip sellers. If you get totally stuck: email the punkies team at punkperformance@hotmail.com
I hope this helps
Also, http://www.fuelsaver-mpg.com/ sells what they call a "Digital EFIE" which addresses the oxygen sensor pretty much the same way as the O2ptimizer does (as a comparator). The DFA and the DigitalEFIE seem to be the best two ways to adjust the fuel on a modern car. :)
Comments
Re: Digital Fuel adjuster
Interesting... This seems like exactly what I want: [quote]Digital Fuel Adjuster
Ref: High Performance Electronic Project for Cars – Silicon Chip Publications.
This unit is a huge revolution in DIY automotive performance. It gives you the power to completely tune the air/fuel ratio throughout the entire load range, at 128 load points, providing incredible mapping resolution and brilliant drivability. It uses the Handheld Digital Controller – KC5386, so there is no need for a laptop, and it supports both static and real-time mapping. It can be used on 0-5V and 0-12V signals, so it is compatible with all voltage output airflow meters and MAP sensors. It can also be set to work with 0-1V signals, allowing modification of EGO sensor signals. This unit has been extensively tested on a wide range of cars including Subaru Impreza WRX and STi, Nissan 200SX, BMW 735i, Lexus LS400, and Nissan Maxima. Kit supplied with PCB, machined case, and all electronic components. Kit requires the Handheld Digital Controller – KC5386. [/quote]
[img]http://www1.jaycar.com.au/products_uploaded/productLarge_8019.jpg[/img]
[quote]QTY 1+ $79.95 5+ $71.95 [/quote]
Maybe most interesting is this: [img]http://www1.jaycar.com.au/images/prodOutOfStock.gif[/img]
Re: Digital Fuel adjuster
Hello,
I have been using the unit now for the past four week. I originally bought the unit to use on the MAP sensor of my Subaru 2.5 Auto liberty to reduce the fuel usage a bit. Started down the HHO path and simply did not get around to building it.
Finally I put it together and fitted it up to control the Ehaust Sensor. With the HHO alone I was able to reduce the fuel consumption from around 9.3 litres per 100 k's to 8.5 then finally i fitted up the digital fuel controller and i am running 7.9 to 8.1 per hundred.
For the last 1000k's I have had the HHO turned off and I am returning 8.5 per hunred, that was really impressive.
What I like about the Digift fuel Adjuster is the ability to totally control what you are trying to control. For example I need to add 0.2volts to the exhaust sensor out put, but i only want to add the volts at a 0.3 to 0.8 volt range. To easy and it can be done on the fly while diving up the highway, no need to stop.
I have now bought a second unit that i will be adding to control the MAP sensor. It will take a while for me to get around to fitting it but I am really looking forward to seeing the next level of improvement.
John Velo Factory Element
Re: Digital Fuel adjuster
Very interesting. To me this sounds like a very good solution. Not as involved as going standalone like a megasquirt or getting into custom cals. Do you have any gauges? EGT or wideband A/F to help tune it?
Re: Digital Fuel adjuster
[quote]I have now bought a second unit that i will be adding to control the MAP sensor. It will take a while for me to get around to fitting it but I am really looking forward to seeing the next level of improvement.[/quote]
Why a second unit? does one unit only control one sensor?
Re: Digital Fuel adjuster
Hi All,
Yes you are right, one device - one unit. The Digital Fuel Adjuster can only accept one input. Though at $79 and about 90minutes to construct it is still pretty good value.
To use the Digital Fuel Adjuster you will need to have a Hand controller, also $79 and a serial cable to link the two together, then the adjustment is easy.
For assistance with tuning I have a couple of good friends that are mechanics so i can have the results checked. The changes I am making are really slight as I am trying to stay on the safe side. My car is used for work and I travel approx 200 k's per day. So in a few days I have a good idea of what worked and what failed.
My apologies for the last reply, i made a number of spelling mistakes I missed in the rush. Hope this one is a little better.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi all,
Just to finish off, I found these two articles on the Digital Fuel Adjuster. They helped me with my decision, I hope they can help you too.
http://autospeed.com/cms/A_2418/article.html http://autospeed.com/cms/A_2420/article.html
John Velo Factory Element
Re: Digital Fuel adjuster
Has me seriously thinking of not going megasquirt... Will still go wideband so I can get a good handle on the A/Fs
Have you done any mods the help support leaner burn? Or just leaning out the factory's overzealous fueling tables? You know what the A/F is?
Re: Digital Fuel adjuster
Hi,
I originally set the car up with another JayCar kit to monitor the A/F. Just the basic kit that enables you to set up to monitor closed and open loop running and a couple warning LED for ratios above 16:1. Of course all this was done with the assist from a mechanic to check. On running the car, the first map I ran caused the car to ping, five minutes later I retuned it. I had made a mistake with the setup, got it close the second time, third time is better again.
The basic setup allows 128 point changes per volt range, for me I am monitoring 0 to 1 volt of Exhaust Sensor, with 128 adjustments in between. I add 0.2 volts to the 0.4 to 0.8 volts and bleed the volts to zero change on each side of the change. The car runs so much smoother under the current config. With the HHO cell in conjunction at a minor 0.5lt per minute the car handles long hill runs without down changing from over drive.
Subaru’s run rich most of the time, so there is some room to move. I leave alone full rich, I leave alone full lean, as I do a lot of 130k of high 110kph driving on the flat and on cruise control it works best. I then spend two hour a day stuck in traffic. What I have found is that for me, saving fuel at idol and getting up to speed is where it needs to be. The highway run is really economical, it’s the stop and start in Sydney traffic that is the killer, it’s only 55k’s of city driving but the average speed for Sydney these days is 22kph due to the traffic.
For me it's all just fun.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi, those are impressive figures for a 2.5L Subaru. What year is it and does it have auto or manual trans? I am just running a custom Efie for the O2 sensor and a voltage adjustable MAP modified signal and I have gone from about 8km/l to around 9.5 km/l mostly urban running with an MY2000 auto 2.5 Heritage wagon. I will be going on a long trip early June with lots of previous km/l readings so that ought to be interesting! I'm also based in Sydney so perhaps we can catch up and compare notes on what does and does not work.
Re: Digital Fuel adjuster
Hello,
Good to hear that someone else is playing the Subaru game for economy, most go for HP. My car is a Aug 1999 Subaru Liberty Heritage sedan with the four speed Auto. Wheels are 18 inch with 215 x 35, the rolling diameter is the same as standard. I have to say the low profile tyres help with consistency, I run 55psi, the change in tyre pressure makes little difference with such small side walls.
Under the bonnet the car is mainly standard, well maintained at the Subaru recommended intervals. I run a K&N panel filter and slightly colder NGK plug to help with the pinging factor if it occurs. Finally I have JayCar Digital Fuel Adjuster on the O2 sensor.
The daily drive is South of Wollongong to Rosebery, 5:45 am leave time in the morning and 4:05pm in the arvo back home 95k’s each way, I do the speed limit everywhere, I don’t see the need to rush. I try to fill up at the Ampol at Kirrawee at the same pump on the way home for consistency. Let me say though, I have filled up in Wollongong and found some really funny fill readings. Dare I say there appears to be some pump cheating going on. I have also had a good friend go to a station with a ten litre drum for their race bikes, the pump says ten litres but only nine is in the drum, so I avoid those stations now.
OK back on the topic, I have not had the chance to get the MaP sensor side running yet, hopefully in the next month. This weekend I hope to add the new Browns Gas Booster I have been working on. For me it is exactly that, a booster to help the octane, never any more than about 0.5lt per minute of gas has given me the best results. So next week I should have more figures to go off.
By all means I would be happy to have chat, you can contact me by email at john@factoryelement.com that is my home email address. Over the next month I will be changing our website to be a factual site around MPG, petrol prices right now are stupid. So any help we can put together for the battling Aussies out there the better. I fill up twice a week at $75 a pop, it’s nuts.
I am interested in hearing about how you have set up the MAP sensor as that is the next project. I look forward to hearing from you soon.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi John,
my Subie is a mid MY2000 2.5L auto Heritage Wagon (heaviest Lib at the time). I used to get abysmal fuel economy when I first bought the car (preloved) 1st owner used to get 350km a tank commuting and 550kms on long trips; not exactly good. I'm up to around 9 - 9.5 km/l commuting (not stop/start). That used to be the avg km/l for a trip up the central coast from the Hills district. I expect better now. Best was about 12km/l on a Canberra trip driver only on the speed limit and again I expect better. I suspect this car came standard with slightly retarded timing as the original performance was pretty dozy.
I've got a complete MRT extractors, high flow cat and exhaust fitted (long story how that came about but not looking for performance) but got it anyway AND better fuel economy.
I've tried lots of things, still using additives, mainly acetone, xylene and napthtalene for about a year now with no bad results except for having to clean the fuel pump filter from brown gunk 3 months in. It gets me about an extra 10%. The MAP modification is the Jeep 5V regulated one, currently running at 4.5V. Incidentally the orig Subaru voltage was 5.12V in one car and 5.16V in another (Outback) Seems the ECU runs a little higher to get aroud poss voltage drops. I also run an EFIE set very aggressively- get the occasional CEL but no probs.
IAT resisters no good. CAI no good, HAI no good, fuel heater no good and PCV jar and atomiser not great but runs a cleaner engine. However this was all trialled before the EFIE so I'll have to do it all again.I've also used Boric acid in the engine oil and through the intake manifold. Bought a Scangauge II to speed up testing but it doesn't work with this model!@#$%^.
I am toying with the idea of using the digital fuel adjuster combined with a wideband O2 sensor as it would give me great readings on AFR while keeping the ECU happy!
I have also to fit an HHO generator but car has to back to MRT for a "tricky bits" dyno tune they still owe me so I need to have the car pretty much standard. I'll be interested in your results with it. That would bring it close to the HAFC setup for a 2.5 Auto except for the fuel heater/ionizer , they claim 60mpg for a 2.5L auto on the highway, that is a 65% improvement on 12.5 km/l EPA.
Best results with MAP and EFIE combeine are only recent BUT repeatable!
My personal email is johnfnielsen@yahoo.com. Cheers John
Re: Digital Fuel adjuster
Hi John,
Sorry about the delay in getting back to you. I took the time out to go back over my own result and see what worked and what has not. I found that a HHO cell worked well, the simple reliability of the device being the biggest issue. After six month use at 3.5 hours per day of driving the cells would be burnt out around the positive terminal and basically fell apart.
Once I had added the Digital Fuel Adjuster I found that my result started to become steady and did not vary a great deal. I don’t know that a wide band O2 sensor would be worth the effort. My setup gives 128 points to modify in a one volt range. I found the first setup that was aggressively setup did not work. My next config was more sensible and mathematically better.
I set it up by dividing the 0-1.0volt by 128 point, that meant that a 0.2volt setting was 27 points on the hand controller. I then looked at what I wanted to achieve. Light to mid throttle change, so 0.4 to 0.8 volt range and added the 27 points to those then 0.1 volt either side I tapered the added volts to zero add. This gave immediate result. It also meant the car stayed within normal full lean and full rich ability. The car runs really well at this range and the base line fuel consumption was now down to 8.4lts per 100 combined City/Hwy.
In the last two weeks I have been using a Novak vapour device. Interesting that I am now seeing 8.1lts combine average, very surprising as the only vacuum line I could use draws no air at idle, only above ¼ throttle would create enough vacuum to draw air through the Novak unit.
I take a very simplistic approach, keep it as close to standard and build from there, one change at a time. I believe every car has the ability to run more efficiently as the manufacturers run them all really rich to make them last through the warrantee period without any needed work. If it was a high end sports car, then they are tuned to go and go hard. The Liberty is a classic small engine heavy car setup so I view it like a taxi. Designed to last and built tough, so there is room to improve.
Really the big thing is knowing where you are starting from and understanding how it works. That can be really hard sometimes. My first mod was a JayCar Fuel Mixture Display, $15, 30 minutes to build and 60 minutes to fit. What this shows is the closed loop / open loop points in my driving style and I adjusted to suit. Then I had the car running as economical as possible before changing anything. That gave me an average of around 9lt / 100 combined running really easy on the throttle. Now my result are better and I am driving harder than I did when setting the base line.
I still haven’t had the time to look at the MAP sensor, three kids is a killer to play time on the car. But I am happy to live with the delays, I am dad first. I have had the performance cars so that is out of my system for now.
My next step will be the new HHO followed by the MAP sensor Digital Fuel Adjuster mod.
John Velo Factory Element
Re: Digital Fuel adjuster
John, have you considered disabling the oxygen sensor (either by disconnecting or supplying a fake signal) and using the DFA to completely tune your car in open loop?
As a keen reader of autospeed myself, I noticed that when the Maxima (one test car for the DFA) was stopped for a roadside emissions check, it was well within spec. With a large air-flow meter bypass, intercooler, modified exhaust, an a disconnected oxygen sensor.
[url]http://blog.autospeed.com/2005/06/26/ooops-meeting-a-random-emissions-test-station-2/[/url]
Is the article where it mentions that.
Maybe you should consider doing that instead? Closed loop wouldn't exist, but then you wouldn't exactly need it either (at least while all of your sensors are working fine anyway).
Re: Digital Fuel adjuster
Hi John,
Autospeed has really interesting reading and some great approaches to problems.
I have thought about removing the O2 sensor from the equation. But have put it further down the list. My thought is that it is there for a reason. Seeing as I am trying to improve what is already on the car and don’t intend on changing to far from that the O2 sensor would be a few steps away.
From memory AutoSpeed had an article where they turned off the O2 sensor on a Prius for particular load readings, I will need to go back and find that article later.
I guess my concern is that removing the O2 sensor would drop the car into an error mode and ultimately have the car run full rich all of the time. That in effect will be worse for economy. I found when the DFA was setup aggressively on the O2 sensor my fuel consumption increased, the new setting have move the reading a little off what the ECU expecting from the O2 sensor and the consumption is really good.
One of the things that is really annoying with the Liberty is the ability to find any one that can tune it for economy, everyone I rang said no, but we can make it go harder. The guys at MRT where the same, basically the response was, not worth the effort to write a program to do that. Maybe at $1.60 plus a litre more people will ask and someone will eventually go sure thing.
Do you remember what wire of the standard Liberty MAP sensor was sending the voltage signal to the ECU?
John Velo Factory Element
Re: Digital Fuel adjuster
If you have a multi-meter it isn't hard to find. On my Legacy GT (Liberty RS) it only had three wires going to it. One was constant 5v, one was earth, and the other is the signal (varies between 0 and 5v, depending on manifold pressure)
Don't the normally aspirated engines have an air-flow meter?
Ben
Re: Digital Fuel adjuster
Thanks Ben,
Sorry about that last reply, i thought you where another Forum user I had been talking with.
I believe it is a MAP or MAF, I have not taken to hard a look at this stage. From memory it is a three wire unit so I will run the Multimeter over it. It is certainly different to the older Liberty and not the same as the WRX my wife had previously.
I will take a look under the bonnet tonight and check it out.
Thanks Ben,
John Velo Factory Element
Re: Digital Fuel adjuster
I figured that, that's why I left my name at the bottom.
Well my GT was a 1990 model with an airflow meter, which is very similar (if not identical) to the early WRX setups. If it only has three wires, and is only connected by a vacuum line, it's a MAP sensor.
My car had both (MAP and MAF), the MAP sensor was primarily used for the fuel cut (overboost protection), and when an obvious fault (ie no connection) with the air-flow meter occurred. Without the turbo, however, your setup is not going to be like mine.
Incedentally, the oxygen sensors would be primarily there to make sure a one-size-fits-all program actually does fit all the cars for the warranty period (and longer). If you are monitoring the output of the oxygen sensor yourself (as a rough guide to rich/lean) and have the ability to tune the car yourself (through the DFA), I see no real reason for keeping closed loop. Especially if you are like me and can't resist pressing the buttons every few days in search of that elusive sweet spot.
Does your car have some kind of distributor? If it does, the new programmable ignition (the one that uses the hand controller) from silicon chip might be something for you. That, with the DFA, would allow you to have a completely programmable fuel/ignition system. Allowing you to take advantage of any combustion enhancing device you may fit.
regards Ben
Re: Digital Fuel adjuster
Thanks Ben,
I know where you are coming from and being in IT you tend to look at the electronics first.
it is definitely a MAP sensor. I also had a 92 wagon that ran on LPG for a number of years. Easy enough to do, even though Subaru say you shouldn't and you can't. 400000k's later the only thing that killed was the idiot that pulled out in front of me. That thing was a rocket on gas, but, 13+lts per 100. Makes the current car at 8 to the 100 nearly the same price to run.
I had a look at Silicon Chip Engine Management, just to much trouble for the amount of time I have free. I will definitely look at going without the O2 sensor. I could in effect use one DFA to intercept and the other to remap the MAP sensor.
Definitely food for thought.
John Velo Factory Element
Re: Digital Fuel adjuster
I'm not exactly sure what you mean by using two DFA's on the same sensor there...
Although with the MAP sensor being a vacuum operated potentiometer, you can do various things to the input voltage as well.
Remember that the problem with intercepting a MAP sensor is that the signal is altered by the same amount at all load sites.
You could try when you have a DFA on the MAP sensor is to disconnect and plug the vacuum line to the fuel pressure regulator. At low loads this will raise the fuel pressure by 10 psi, tapering off to zero at high loads (21 inches of mercury is maximum vacuum on decel for my GT. It idles at 18, and cruises at 14. Disconnecting that line would raise fuel pressure by 10.3, 8.8, and 6.8 psi respectively under those conditions). You can correct for this with the DFA on the MAP sensor. The theory is that higher pressures and lower pulsewidth delivers the same amount of fuel through the same injectors, but with a better (finer and more consistant) spray pattern, for better vaporisation. At high loads it will be stock fuel pressure.
All of this I would do on my current car (an EF Falcon) if it had a voltage outputting load sensor. All I have to (not play with :( ) is a frequency outputting MAP sensor. Worst of both worlds...
Re: Digital Fuel adjuster
Hi John,
Quite a mixup in posts! Never mind, the early Liberty's (nee Legacy) with the quad cam motor ran MAF sensors. The SOHC 2.5 have a combined MAP and IAT device mounted on the manifold. In Australia it is available on RX and Heritage from late 1999 onwards. Don't know off hand which wire is the 5V return. Bear in mind that I tapped into the 5V ECU supply side and varied that down in order to get advanced timing and leaner mixtures. The reduced 5V supply also affects the IAT output, making the ECU think that it is hotter. It may also retard the ignition but I think the MAP sensor overwrites that.
I got to build that Jaycar AFR meter and see what the mixtures are doing, I'm using the LED mixture meter since about 1995. It keeps me entertained! What HHO generator do you have and what gas volume are you aiming for? I know exactly where to put the gas, the vacuum port you describe is the one I use for upper cylinder cleaning and also water/metho mixture (metered) to help cleanup any carbon deposits. I don't use it all the time just prior to every 25,000 km service. I've also read up on dual entry for the gas, one after the throttle body for light throttle and one before for WOT.
I'll pull the MAP sensor in daylight and let you know the wiring colors.
Cheers John N
Re: Digital Fuel adjuster
Hi John and Ben,
Thanks for the replies.
Ben, I am looking at running the Current DFA on the O2 Sensor and the second on the MAP sensor, but I really am going to think about the operation after your findings. The DFA can be set to any load at any range based around the 5V out put, even off setting it slightly may make a difference. Food for thought I guess.
John N, My car is August 1999 so it is probably going to be one or the other. Where is the IAT device located?
On the HHO front, it is on the bench at the moment. I have lathed up some nylon ends, I run a small plate size. 150mm x 30mm in a Pos/neg with five sets at 1mm gap. I am building this currently and will get it together over the next few days if time permits. Once together I will email you some photos. The aim short term is one litre per minute at 10 to 15 amp. Once up and running I am going to build a second unit and daisy chain them so one feeds the other.
The old one was similar, put had 7 plates and ran just under one litre per minute at 20 amps. It simply fell apart, to much current, to much heat. I have cut this one up to take photos
Gas input is through the main inlet for the throttle body. Have a look at you tube, I believe that ZeroFossilFuels had an article on it.
OK time to get back to work.
Thanks guys, John Velo Factory Element
Re: Digital Fuel adjuster
Hi John,
The IAT and Map sensor combined unit on my Sub (feb 2000) is located to the right of the igniter module,the 4 legged spider thing that the spark plug leads come out of. I think it is a 4 lead plug connector. If you cannot locate it your car may be running a MAF sensor which would be located in the tube before the aircleaner box. I'm pretty sure your model (Gen3) should have the combined map/IAT sender.
I have modified the EFIE to activate and simulate the waveform at a super low 50 - 100mV after looking at the O2 sensor output curve. Because of the steepness of the curve around stoich a 200mV trigger point would only yield about 15 to 1 whereas a 50mV trigger would yield aroud 16 to 1. I can easily run that ratio given acetone/xylene additive mix and the fact that Subies tend to run rich anyway. There is no noticable effect on drivability, if anything the car steps off better!
Leaning out is confirmed by the Led O2 indicator kit, it is spending much more time in the lean rather than average setting. Sometimes it shows no reading at all for a time then starts up again. At higher settings there is not much difference to standard.
Cheers John N
Re: Digital Fuel adjuster
Hi John,
Thanks for that, Yes mine is the same. I wasn’t too sure what the IAT was as I appear to have a device on the right hand side of the throttle body, looking the car from the grill. I thought that may have been a throttle position sensor. But I really need to get under the bonnet of the next few days. Time just has not permitted any fun activities of late.
When the O2 sensor is showing no reading the car is in either full lean off throttle mode, or relying only on the MAP sensor output for fuel requirements. Speaking with a friend that does a lot of ECU mods out of their work shop ( mainly for performance, they do a lot of super street drag cars ), he recommended always down changing to third when rolling down hills or to a stop as it forces the ECU to shut down the injector in these conditions. If I employ that tactic I have found that I regularly hit the 8.0 Lt/100k range. Yeah I do a large down the mountain run into Wollongong.
I will do some research into the other box and see what I can finds out.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi John,
the device just to the right of the throttle body is indeed the throttle position sensor. The MAP/IAT sensor is directly to the right of the igniter further towards the front of the car. To gain easier access it is helpful to disconnect the #4 cylinder spark plug lead at the igniter. Furthest towards the rear and on the right.
I think there are 4 leads, 5V ecu out (mine measured 5.11V) IAT out (this varies with air temp) MAP out (this varies when you idle and blip the throttle) and the 4th ????(earth?? ) I cut the 5V ECU out wire and substituted the ajustable voltage regulator. This affects both the MAP and IAT outputs of course and there will be a point where the perceived higher air temp will retard the ignition again although it will help to lean out the fuel mixture a little. This will not happen if you use a DFA on the MAP output end. Hope this helps.
John N
Re: Digital Fuel adjuster
Thanks John,
I will set some time aside this weekend to take a good look at it all in more detail. The MAP sensor sounds like real bugger to play with. The older 2.2 Liberty I had with the Air Flow Meter which appears to sounds like it would have been a lot easier to adjust. My other thought, but I still need to research, it is to maybe adjust the out put from the TPS. The throttle position sensor has to be recording back the opening to ECU and inturn have some effect on the fuel input. I also would imagine this would be a voltage setting. I believe there maybe an article on this in the performance electronics mag from Silicon Chip.
I also hope to get 2 hours to finish off the HHO Booster this weekend, I will get some photos through to you when I am done. It feels like months now since i started on itand it is still sitting there. Bring on the long weekend.
Again, thanks for you help. It will save me a stack of time.
John Velo Factory Element
Re: Digital Fuel adjuster
On most cars the TPS is only used to calculate shift points, and idle/cruise/WOT conditions. In normal driving in a manual it effectively only controls when closed loop is to be used. It is also used as a backup when the primary load sensor fails.
I re-read my previous post and realised I said something wrong. The altering the MAP sensor signal will effect the entire RPM band at once (when at that load). An example is that a MAP sensor on a naturally aspirated engine will show 5V from idle to redline if the throttle is open.
So you can lean out low loads, but ALL low load sites will be affected. However, since the engine isn't actually doing much at 4000rpm with 14 inches of vacuum, it probably doesn't matter much. Seriously, when was the last time you were two gears lower than you should be for long enough to notice a flat spot?
Re: Digital Fuel adjuster
Hi Ben,
I did a little research last night as well and had the same opinion of the operation.
Even more so my car is an auto, so it is even less likely to be in the wrong gear.
I will do some reading on the forum later tonight to see what other have done as well with the MAP sensor.
Thanks heaps for you thoughts and findings.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi all,
After 6 plus years of on/off experimentation with 5-6 different cars I'm finally getting somewhere! In the latest car (Subaru Heritage 2.5L Auto Wagon) I have reduced fuel usage from about 7-7.5Kms/ltr to latest 9.5-9.7kms/ltr using 6week moving average results, full tank to full tank average trip around 400kms between fills. All urban running with some free flowing motorway occassionally. Best on highway now 13kms/ltr.
I use the following: acetone,xylene, upper cyl lube and naphtalene added to fuel at fillup Engine and fuel system Ba treated-had some filter blockage issues EFIE (not the ER one) set to give 1V deflection at 50mv input MAP voltage at around 4.5V instead of standard 5.11V PCV canister with fuel bleed at max 3ltrs/hour using model airplane needle valves Basic Hot air intake.
Next step is to complete AFR meter and install part of HAFC hho generator. Locate and install CTS compensation, probably using thermistor and fixed resistor. Install O2 extender if obtainable. Is there anyone willing to help me get a special Stant thermostat and the Help! 42009 spark plug non fouler from Autozone and ship to Australia at my cost please please- cannot get these items in Oz and no stockists will send O/S I have Paypal so can easily send funds and USPS Global priority mail is pretty cheap! Just PM me.... Seeing I cannot get my scangauge II to work with this car I may buy a fuel injector duty cycle kit from Jaycar to study more immediate effects of my tinkering. A week to wait for results is a long time......
I'm told an identical car achieved over 60mpg higway in the HAFC blurb..... so there is still much work to do.
Re: Digital Fuel adjuster
Hi John,
It is good to hear that you are making some head way. I also saw the HFAC guys saying they are getting 60MPG on the highway from an Auto Liberty 2.5. That’s 3.9lts per 100? Kind of depressing when you look at the target we are setting ourselves.
Looking at the result and what you are achieving, while good compared to where you where with MPG, I am left a little puzzelled. My reason for this is that currently I am only running the DFA on the O2 sensor and constantly return high 11 to mid 12 kilometers per liter with E10. No additives nothing. For example I see 610 k’s on my tank prior to the fuel light coming on, I can almost set my clock by it.
I am just wondering if something you have added is stopping you going further with the mods you currently have, is one of them maybe holding you back. It is just a thought and maybe a revisit of the mods you have made to check their effectiveness will result in a dramatic improvement.
I do have a question on the MAP sensor, the vacuum line that comes from that runs out to a small box with a power circuit. Do you have one on your car and do you know what it is called. Running a Novak Water Vapor a month or so back as a test had me wondering if that is the right place for it and what I am effecting. To date I have not been able to find out what the box is.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi John,
Yes my fuel economy is kind of depressing. When I first bought the car s/h it felt a little dozy compared to my previous RX auto (the quad cam model) but otherwise the car was in great condition. I thought it was just tuning but the previous owner said he got 350km/tank urban and 550km/tank highway. Not great. I have seen as low as 6km/ltr in stop start commuting! The mileage I am referring to is strictly urban running with stop start traffic and the occassional 80 km run. On a trip to Canberra I averaged 8.2 ltrs/100, don't know what it would do now.
I normally travel to the snow regularly but there isn't any yet this year so no long distance cruising mpg yet. Your mileage is impressive, I'm envious, however mine seems to be more in line with forum topics at Ozliberty and MRTrally.
From your description you have a different map sensor, mine is attached to the manifold with no vacuum tubes at all. Probably worth a look and compare cars sometime. Apropos the various mods I have documented what improves and doesn't improve things. There has been an occassion the car had to be bog standard and in that form it promptly dropped to 8kms/ltr where I now get around 9.5 kms/ltr.
I agree it's a long way to 3.9 ltrs/100 but that is what makes life interesting!
Cheers JohnN
Re: Digital Fuel adjuster
Hi John,
I was lucky with my car, an old guy owned it from new full history, nothing but Subaru servicing. Then I bought it. I just have to think that something is in the way on your car. It was poor from day one which makes me think your effort are being sabotaged by some hidden gremlin.
My driving is split 50/50 in time between HWY/City. Maybe it’s my grey hair driving style. But even nothing but city I get just under 600k’s before the light comes on. Prior to the DFA it was 520k’s HWY and the light was on. I have had a few runs lately at 130> on the freeway for 70 odd k’s, plenty of hard acceleration in traffic and still return 11k’s per litre.
My glove box manual says the car will do 6.8HWY/9.3City. So for now my target is 6.8 combined. Achievable I believe.
Just from our conversation on the forum I have some items under the bonnet that I can’t find any info on, so today I order a workshop manual from Repco. It will be interesting. I know early 1999 Gen3’s had a MAF and late 1999 Gen3 had a MAP sensor. But I am wondering if there is another in between one? The manual will give me some pointers I am sure.
I will be back on HHO after the weekend, so it will be interesting to see how it goes.
I will try and get some photos through to you soon.
John Velo Factory Element
Re: Digital Fuel adjuster
I'd like to test a pair of the Digital Fuel Adjusters on my '99 F150... Are they even available in the US? I couldn't seem to find the order page. Either that, or the "out of stock" page replaces the order page. :(
Re: Digital Fuel adjuster
Hi Mr Pinhead ( it just did not seem right without the MR infront ),
You should be able to get them through JayCar Canada if you need on this email address:
techstore@jaycarelectronics.com
or phone number:
Techstore USA/Canada 1800 784 0263
In Australia they are easy to pick up generally three or four on the shelf at all times. Checking the site I would say the warehouse may be out of stock but the retail stores have them on the shelf.
You will need the DFA ( one for each sensor) plus a hand controller. If you have any issues locally I am sure I can arrange to go up get them for you and send them over. We can arrange payment through paypal and air mail with insurance with out to much effort.
Anything to help out.
John Velo Factory Element
Re: Digital Fuel adjuster
HI! There, I'm new to this forum and glad to find it has lots if info, my situation is i'm in the process of buying all the parts for HHO cell on my 01 subaru forester, it has a stock 6 wire bosch 02 wideband part # 17018 on the front and from what i have read it looks like the Jaycar DFA is one my solutions to adjust my wideband , is their anyway cheaper?? I am also running a hi flo cat,do i need to do anything to the rear 02?? Also not sure what my options are for the AIT/MAP?? for parts to adjust, i do have an eagle research efie from 98 forester not sure if it can be used.?I'm also not sure the best place to connect the hho hose and i think i should have 2 different connection 1 on intake and other near throttle body intake?? thanks for any help. sorry for . many??? Brett Canada. :?: :wink:
Re: Digital Fuel adjuster
Hi Brett,
My understanding of the Eagle Research Efie would say use it. Only the front O2 sensor will need to be monitored. It is designed to simply add a positive voltage step, so 1v or 5v should work.
Myself I am going to madify the MAP sensor with the second DFA I have pruchased. Should start the build this week.
With the HHO I run mine to the air filter side of the throttle body, through the side of the intake trumpet. Once I have ironed out the final bits and pieces sorted out I will fit a proper LPG plenium to give better results for HHO mix.
I hope that helps,
John Velo Factory Element
Re: Digital Fuel adjuster
HI! John, Thanks for your help , will be a few weeks before i get all my ordered parts to gether , i can connect my efie up and my laptop with elmscan software and see how the efie will work before and after HHo install. Will probably have more questions. Will keep you guys posted .Thanks John.
Re: Digital Fuel adjuster
Hello John ( from earlier in the thread ),
After a lot of trouble getting the second DFA running on my 1999. Not to sure what was wrong with the device, I bought another unit and had it up and running in about three hours.
Any way back to it, i have added the DFA to the output signal of my Subaru MAP sensor. Set the DFA to start after the engine is running and I am now returning good milage with HHO. I am hitting 8\100.
Every other time I have run the HHO the ecomomy would go out to 8.3+\100. so this is a good starting point and I can modify the signal MAP to hopefully get deeper into the 7's per 100k's.
OK back to the fun part.
John Velo Factory Element
Re: Digital Fuel adjuster
Hey there DFA users... I have just built my DFA and Hand Controller unit and cant get past the first testing/calibrating step. Hoping someone has had this issue and knows a fix. I have been emailing back and forth with a guy from jaycar and it seems that I have everything built and put together properly. When I put power (using my truck while running 13.8v) to the DFA as per the instructions, I get a quick flash from the LED and hear a click which I assume is the relay. There is 13 volts going in and I am reading 2.25v on TP2. SCR1 shows almost 1 volt which I am told it should. There is no power going to the hand controller (it has the correct cable). The pot VR4 that adjust the turn on power seems to have no affect when turned either way. ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? I hope you all can help... [-o< [-o< [-o< [-o< Thanks
Re: Digital Fuel adjuster
Ahh, the pain I do feel it.
I have built three of these units now. The second one is on the shelf in the shed, could never get to run, checked checked and checked again, change all major components, many hours and days waisted. Same thing the RED LED would flash then go out. I ended out buying a third unit which was up an running with in three hours. I am wondering if there is a batch of them that is dud.
I have not had the time to finally sit down and work out the difference between the three units, I did notice that one of the parts was different the BC327 in the two units that do work was on a card board strip with the pins straight not stepped. I have not gone back to JayCar to pick up a replacement part.
The LED must stay on for the unit to work.
If the LED is staying on, the hand controller must be attached prior to powering on the DFA. If that is the case hand contoller attached, DFA powered on and the LED is on. But the hand controller is not lighting up, then you need to adjust the trimpot in the hand controller, it controls the brightness of the display, from out to on. That one took me a while first time out.
Let me know if either of those is the issue and I will compare mine for you.
John Velo Factory Element
Re: Digital Fuel adjuster
Thanks John. I will see if I cant find a bc327 chip to put in there.
Re: Digital Fuel adjuster
How did you get on with your DFA, have you been able to get it working?
I still have one that sinply will not run. All major components replaced and still it does not start the curcuit when power is applied.
John Velo Factory Element
Re: Digital Fuel adjuster
Hi Notsure,
Ok final I have the answer to why the second DFA I had was not working. Seriously I can't believe it. I have change all major components. Still no good, finally I had an hour free and caught the manager of my local JayCar store. Asked if he could check it for me.
Ten minutes later he turned and said the 330r and 330k resistors are in the wrong spot. We changed them around and bingo, it works.
The pain I went through,I simply could not see it to save my life.
So to Chris the manager of the Wollongong JayCar store, THANK YOU!!
John Velo Factory Element
Re: Digital Fuel adjuster
[quote="Atechguy"]HI! There, I'm new to this forum and glad to find it has lots if info, my situation is i'm in the process of buying all the parts for HHO cell on my 01 subaru forester, it has a stock 6 wire bosch 02 wideband part # 17018 on the front and from what i have read it looks like the Jaycar DFA is one my solutions to adjust my wideband , is their anyway cheaper?? I am also running a hi flo cat,do i need to do anything to the rear 02?? Also not sure what my options are for the AIT/MAP?? for parts to adjust, i do have an eagle research efie from 98 forester not sure if it can be used.?I'm also not sure the best place to connect the hho hose and i think i should have 2 different connection 1 on intake and other near throttle body intake?? thanks for any help. sorry for . many??? Brett Canada. :?: :wink:[/quote] Brett, My experience with the 6-wire O2s is that the EFIE cannot possibly work. I got best results by putting resistance in the signal wire. On the Kia I tuned it ended up being 180 ohms. Hope that helps.
Mike
Re: Digital Fuel adjuster
Fuel_Element
you asked____ I do have a question on the MAP sensor, the vacuum line that comes from that runs out to a small box with a power circuit. Do you have one on your car and do you know what it is called. Running a Novak Water Vapor a month or so back as a test had me wondering if that is the right place for it and what I am effecting. To date I have not been able to find out what the box is.
John Velo Factory Element
Answer_-- If you are looking form the front of the motor (I have an 01forrerster 2.5L) the thing you spoke of runs out towards you and has a thermistor and vacuum line attached! THAt is the Idle air control Valve___I would mess with it...that little jewel keeps your car from surging at idle or at least I beleive that is what is does...none the less it is the idle air control valve...
***I have been all over the web looking for the answers to beat my Suby so I can get my HHO running___and would like to say thanks for all of the info :lol:
Another note as far as that little water vapor cannister mentioned here! I also have TWO Pond Foggers set-up that are ni my car ready to go____going to try cool distiled water/alcohol vapor first with the NEWLY discovered answers I found here as far as my electronics go! check out foggers on youtube! I got mine off of Ebay...the thread was actually found on another fuel saving sit. simple to install the ones I got do 300ml on 24v's at 1200ma...got a 400 watt inverter so I can run both! Stuck them in an ABS can just like i would a HHO gen....ran a plastic fuel filter on the vent to introduce air into the can then hooked a PCV cleanng can and plugged my intake into it! SO my cool water/alcohol vapor will be sucked into the vacuum side in between the engine block and intake through the PCV loop.... going to run 91% alcohol at around 50/50 distilled
This guy built a monster unit (10 head) http://www.youtube.com/watch?v=yspJ5SApwIc
or this guy http://www.youtube.com/watch?v=l37U7D8AnwU&feature=related
THANKS again for all of the great info =D>
Re: HYIP - what's this?, Anyone dealt with high yields?
Gone gone... nevery mind ...move along move along
Re: Digital Fuel adjuster
Hey guys just to let you know. If you do not want the trouble of assembling the Jaycar DFAS. Silicon Chip Magazine and JayCar have allowed Punk_Performance to do a commercial version of their DFA unit. well priced at $299.99 and a bit more stylish. All units are checked and tested before post. They are on the Punk_performance website as well as listed on eBay if you want to sought through those dodgy chip sellers. If you get totally stuck: email the punkies team at punkperformance@hotmail.com I hope this helps
Re: Digital Fuel adjuster
Also, http://www.fuelsaver-mpg.com/ sells what they call a "Digital EFIE" which addresses the oxygen sensor pretty much the same way as the O2ptimizer does (as a comparator). The DFA and the DigitalEFIE seem to be the best two ways to adjust the fuel on a modern car. :)