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Edit: if you found this thread trying to fix similar issues - make sure you read it till the before making conclusions
Hi, guys!
I have a 96 GC8 with what appears to be STi V2 engine with 5th injector on top and currently it's setup to run on V4 ESL ECU.
Whole intake manifold is V4, turbo is VF28, injectors are inexpensive 850cc JECS from ebay, ignition is newage COP wired in to run in batch fire configuration. IAT is wired as per ESL manual, and installed in the center of the manifold where V4 coil pack used to be. GM 3 bar MAP sensor is installed as well because stock V2 one is expeced to max out. Wiring is all V2 with patch harness used to convert 4-plug harness to 3-plug V4 ECU with some minor modifications to the harness in engine bay where plugs where different. Basically I did this because I had V4 ESL ecu, had spare V4 engine with broken valve and wanted more from my track car with V2 engine.
I'm new to ECU tuning, know some theory but this is first car I'm properly messing with alone. I managed to dial in all new sensors, tested MAP and IAT readings, everything looks fine. Scaled injectors (I believe scale is set to 0.7) and car is basically starts and drives fine on stock fuel and ignition maps. In fact, current map is stock one except for sensors scaling. AFRs are a bit rich in light and moderate loads, haven't tried WOT pulls.
The problem is that occasionally I have check engine light which reads as ICV error. Strangely it appears during steady highway drive or off-throttle coasting. I tried swapping spare ICV, but it seems to be the same. Also RPM sometimes floats on idle a bit and I can't sort it out. I noticed that adjusting position of TPS on throttle body seriously affects this and ECU "wants" to see certain load on idle, which seems to trigger some sort of Idle mode when ignition is fixed to 15 degrees and not affected by ignition map. This all was very confusing because I haven't seen anything in the manual about it and I can't find any setting to adjust that affect idle in any way except for idle RPM vs coolant temp map.
Are there any tricks to have car idling smoothly? Certain load or TPS position on idle (i have 5% currently)?
I also noticed that pressing brakes hard seem to affect idle as well, need to check for intake leaks, put probably somebody can give me advise what to look for?
Also, do I need to mess with MAF scaling in MAF-less mode?
Last edited by homebuiltracing; 24 August 2019 at 10:07 PM.
Ok, it seems that I wasn't able to read the manual properly...
"When moving to MAFless operation, the calculations are modified as shown in Figure 9. The MAP sensor is no longer used to measure barometric pressure, as it is required to give continuous readings for engine load, so the barometric pressure calculation is replaced with a constant. The computed 16-bit pressure value is then multiplied by the MAF scale parameter. This must be used to rescale the MAP sensor output to ensure the engine load internal units are a close match to those that would have been generated by the MAF computation. Note that due to linearity of the pressure sensor and the volumetric efficiency of the engine, at low engine speeds and load the VE is very low and the fuelling table will need significant amounts of fuel taken out of it. This region of the map should not be used to set the MAF scale factor; this should be set based on how the load evolves when VE is much higher and the load figure more representative."
I never touched MAF scale and form what I see in the map I had on my V4 car that was running on this ECU mapped by professional, MAF scale should be changed.. It also has different values in MAF calibration, not sure about it though...
anyway, probably my Injector scale should be set lower and MAF scale should be used to get load back to normal values, because now I got car running basically adjusting injector scale. I wonder how it runs now on stock fuel map so close to stoich at all )))
Still, if somebody can share any info on this, any help is appreciated...
Last edited by homebuiltracing; 03 July 2019 at 04:43 PM.
0.7 seems a little high for your injector scale - try and 0.6 once you've set your TPS base position (measure 0.5v or less throttle closed). Also have you checked to make sure your using a MAF scale that matches your MAF sensor? Wrong maf scale will throw off the injector scale, fuel table, ignition table etc. due to incorrect load readings.
Once you get it in a state where it's driving, I'd pull a few degrees across the board from the timing map and do a quick run on boost to see how your AFR's look. If they are still quite far out then continue to adjust the injector scale until your closer to correct - then adjust the fuel table targets for fine corrections as needed.
For the size of the injectors and your target boost being more than 1.7bar - you're going to end up speed density so might as well make a start on that now, read the manual a few times so you know what your trying to achieve and sure if you get stuck feel free to give me a shout I'll help if i can.
Thanks for your input!
Car is running mafless already and indeed I had to use MAF scaling parameter instead of messing only with inj scale and wierd stuff like physical TPS adjustment...
Will try to fix this asap. and start from there. this car never run on MAF in current config because it used to be V2...
Still can't believe it starts and drives fine with my initial setup )
ok so - if your mafless then yes adjust the maf scaling to get your load properly scaled and don't forget to switch your fuel table to raw values and do all your fuelling with the wideband and you should be good to go. You'll usually have to make a fairly drastic adjustment at idle so don't be alarmed if it starts looking really really strange numbers from idle to actually driving the car.
Most likely you'll have to do some further adjustment once you get it actually running and on boost - but that's normal enough as well.
Well, got to play with it a bit, and I still missing some important bits of understanding how it works...
I managed to get a drivable map playing with MAF scale and injector scale from the scratch only to find out that it maxes out load at 0.6 bar of boost.. So now i need either to re-scale all tables, or come up with another MAF scale and inj scale combination to get it running within current load range. Max load in fuel map was 48, as per stock map.
From what I saw in the manual, in MAFless mode MAP sensor readings are scaled with MAF scale parameter after MAP scale and offset, so my understanding was that I it should be OK to use older MAFless maps I got when my car was tuned by a pro, if MAP sensor calibrated correctly. I have my GM 3 BAR map dialed in, I can see correct MAP values in log, verified with mechanical gauge and my electronic boost gauge. It appears not to be the case because after I used one of those maps with only injector scale adjusted, car didn't ran even close to expected AFR targets... But I saw some clues like re-scaled axis and fuel map corrections, so I started process from scratch once again...
Can someone help me with "normal" load value on idle for V4 ECU? Currently I have it running around 8-9 and I believe it' a bit high because all maps I've seen including the ones I had running nice in mafless mode on another car are starting from load at 3. Idling at 8 i loose couple of lines in the map..
Is there a way to calculate max load based on calibration parameters to scale it properly to desired boost level and scale all the maps accordingly?
What inj scale people use with 850cc injectors? Mathematically considering that stock injectors were 440cc it should be .52, I believe, but it seems that I can make it run with any value using different MAF scale, so maybe some combinations work better than others?
Currently I started once again from scratch with "realistic" 0.52 injector scale and 25800 MAF scale and tables with max load at 58. Car idles OK and idle cells in fuel map are quite a big drop from nearby ranges, as been mentioned before, but I haven't driven car to see ho it will behave in other areas.. The idea behind such high MAF scale is to see how it will affect load values at the same boost lever to get understanding how much max load I can expect..
Last edited by homebuiltracing; 08 July 2019 at 10:13 AM.
for mafless cars I normally try to adjust the maf scale so that the load works out around 24 per bar. If your planning to run say 1.5 bar boost (so that's 2.5 bar absolute) your peak load would be around 24*2.5 = 60 so adjust your maf scaler until peak load is in and around that region. If your vac at idle is -0.5 bar (around 0.5 bar absolute) then you should be reading around 8-12 at idle. So your table will scale from 8 to 60 engine load (or 8 to 80 if you want to scale a little further into your map sensor range).
In saying that, i've seen plenty of pro tunes that scale from 8 to 120 and the car drives perfectly fine - as you've already found by playing with the maf scale/injector scale values there's a few different ways to skin the cat. Just keep in mind that there are items of the map logic that you don't have access too directly but you will be having an impact on by proxy (like injector latency/tip in values). So you may find that your injector scale needs to move a little one way or the other to get those hidden/undisclosed items just as they should be.
Thanks for you input!
Just checked log of my idle on current test map and it has -0.7 bar on idle (matches boost gauge) and load at around 10-11..
All those non-avalilable items are the reason I'm trying to keep all the values as close to stock or proven maps as I can, because being a beginner and without deep understanding how this particular system works, I'm afraid to break stuff )))
Will try to test drive it in the evening, see how load values change from idle to 0 or some low boost situation and extrapolate that to desired full boost to see if I got that scaling right...
So, after several attempts to re-write my fuel map I'm kind of out of ideas.
I managed to get fuel map to the state when it's derivable and I get nice AFRs all over the map (car is currently boosts only to 0.7 bar)
BUT! Whenever I go full throttle quickly, especially on lower RPM or in higher gears I get instant misfires and AFRs are mess. From logs I see AFR drop below 9 and then raising over 15 due to misfiring.. While this happen and while I keep foot down, RPMs are not climbing or even go down a bit. If I release throttle a bit - car goes fine.
I thought that problem was with throttle tip in enrichment and since it's not accessible in ESL I tried to change injector scaling to solve this.
I used all the scales from 0.7 down to 0.45 and I still have this issue. I'ts definitely rougher on higher injector scales but still present on lower ones. I probably could try go for lower scale but with 0.45 I basically ran out of fuel map! I have to keep idle area values over 150 and my high load area is basically maxed out at 255 - that's not what I expect to have on car car running 1 bar boost on 850 cc injectors... I tried to use lower injector scale and increase fuel map scale to get the resolution back, but it feels like it makes things with misfires worse. With no solid understanding how all parameters affect tip in enrichment I feel a bit tired of this thing...
Can anyone give me any advice to clear things out? I plan to hook up fuel pressure sensor to monitor that because fuel pump is old and might contribute to the iusse, but since this problem clearly happens if I go WOT while not in boost - I don't thing there's a big chance of this..
Cheap 850cc JECS injectors from ebay are also might be an issue, but my friend has car driving fine on Apexi PFC...
cheap ebay "jecs looking" injectors I would definitely be steering clear of - have you had them flow tested and spray pattern checked as there can be a lot of variation with ebay parts. If you can post maybe a log and a copy of the map it was made from it could help people try to help you out more.
Did you get your maf scaling sorted so that idle/boost/cruise readings are all roughly what they should be? After that your injector scale should be somewhere in the region of 0.4-0.5 *if* your injectors are doing what they are supposed to be doing. Are you still using the standard fuel regulator?
What scaling was used on your friends PFC and are they exactly the same brand/type of injector?
If it helps any, i took a set of ebays finest injectors out of a car because the idle was terrible no matter what was done in the map, after flow testing it turned out the injectors didn't have a spray pattern - more like a little pencil beam of fuel. Replaced with a set of 440's with rail adapters and job done.
cheap ebay "jecs looking" injectors I would definitely be steering clear of - have you had them flow tested and spray pattern checked as there can be a lot of variation with ebay parts. If you can post maybe a log and a copy of the map it was made from it could help people try to help you out more.
log and copy of the map is attached. Fuel map is sort of rough estimation, just to test new injector scale. it basically allowed me to confirm that issue is still there and keep AFRs in "OK" range while testing, it's not something dialed in... Map is esl file in zip, couldn't attach it otherwise...
You can check any spot when throttle is at max (78.1%, I believe) and you'll see that while it's planted rpm are kind of fluctuate and not increasing and MAP is climbing at the same time... If I apply throttle slowly it's much better and response is good
Originally Posted by bludgod
Did you get your maf scaling sorted so that idle/boost/cruise readings are all roughly what they should be? After that your injector scale should be somewhere in the region of 0.4-0.5 *if* your injectors are doing what they are supposed to be doing. Are you still using the standard fuel regulator?
Car is running mafless. MAF scale is to get around 24 load per 0.5 bar of boost..
Originally Posted by bludgod
What scaling was used on your friends PFC and are they exactly the same brand/type of injector?
don't have details but i'm sure that they just used dead times and flow info provided by the seller.
Originally Posted by bludgod
If it helps any, i took a set of ebays finest injectors out of a car because the idle was terrible no matter what was done in the map, after flow testing it turned out the injectors didn't have a spray pattern - more like a little pencil beam of fuel. Replaced with a set of 440's with rail adapters and job done.
seller of this lot is local from Cyprus, so I can visit them if necessary ))) Anyway, car idles and drives fine at light loads and with slow throttle increase. The only problem is fast WOT throttle wen it starts to misfire, because of flooding as per my understanding...
Last edited by homebuiltracing; 31 July 2019 at 10:26 AM.
One thing crossed my mind... ECU currently doesn't see VSS2 signal.. it's V4 ecu swapped in V2 car and older style dash sends 5v signal when ECU needs 12v square wave.. [edit: wrong, it also needs 5v]
I'm working on fixing that, but for now I thought that the only issue that it's causing is ICV malfunction check engine code that pops up every time I coast in gear for any significant time.. Once rpm gets back to idle, it disappears... Is it possible that tip-in issue may be related to this as well?
Last edited by homebuiltracing; 12 August 2019 at 07:26 AM.
Yeah so looking in your idle region here your fuel target is still like 152/140 - I'd be expecting that to be more like 80-90ish with the injector scale moved around to suit which should give you a little more headroom up top. What conversion factor are you using for your wideband (just so im seeing the readings correctly)?
Yeah so looking in your idle region here your fuel target is still like 152/140 - I'd be expecting that to be more like 80-90ish with the injector scale moved around to suit which should give you a little more headroom up top.
Been there, with scale at around 0.6...0.7 it wants around 90 target fuel in raw values, but misfiring situation hits harder and is much easier to trigger it with fast throttle application. that's why I lowered injector scale in hope that it will solve this issue...
In fact it's kind of strange because I had other car mapped by pro on this ECU, it was stock EJ20K with 440 injectors and looking at maps that were used, it had injector scale at 0.7 as well. Probably need to verify injectors flow in the first place...
Also as mentioned above, I use GM 3 bar MAP sensor which if it matters... right now it calibrated OK and shows values in log that match my boost gauge and verified with another mechanical pressure gauge...
Originally Posted by bludgod
What conversion factor are you using for your wideband (just so im seeing the readings correctly)?
Yep, sorry about that, forgot that there's only volts in the log. It's innovate MTX-L, 0v=7.35 AFR, 5v=22.39 AFR
yes, will check them... I just don't understand what problem with injectors can cause problems with fast throttle response..
as I said, on light loads, idle and slow throttle inputs it's now 100% normal... More like a tuning/ECU thing to me...
Again, if it was under boost, I'd also was looking at ignition setup which also has some mods on my car... But it's basically the same off-boost...
Last edited by homebuiltracing; 31 July 2019 at 01:49 PM.
Well, I manged to revive my 440cc injectors and everything works just fine. I aslo spoke with some tuners I know and at this moment I'm sure that ESL just not meant to work with injectors that big.. Adjustments and tables necessary to make them work right are just not available. I remember seeing posts about ESL blue car working fine with huge injectors, and I wonder how they did it.. Maybe motorsport-featured version has some extra possibilities and or they had some prototype version of the board, I don't know..
Or my memory can be playing games with me because I spent couple of hours trying to figure out a way to pull 5v VSS2 signal to 12V just to find out that both ECUs actually need 5v signal.. Don't know where I saw that info about 12v signal...
Anyway... I tried everything I could think of with the stuff available in the software and it had no effect on the issue.. Probably 850cc have to wait for another ECU )))
OP is running the v3/4 ESL so should be no issue on 550+'s
I'm running 740's with no problems.
Yes, I have 97/98 esl. Bought it in 2012 and I'm not aware that they got something newer...
What injectors scale do you use with 740s?
Here is ESL demo car running 780: http://www.enduringsolutions.com/fea...sl-demo-wagon/
Still, I'm sure that my car probably could make decent Dyno graph, it's transitions that I have troubles with...
Little update.. Was tuning the car over the weekend on 440cc injectors and had hard times getting it richer than 12 on higher loads... Hooked up fuel pressure sensor and looks like my fuel pump is dying.. Pressure drops about 1 bar on longer pulls.. I wonder if this could contribute to my issues with big injectors before...
Wanted to change my old fuel pump for ages and now got chasing my tail because of it... again...
Also on these 440cc injectors car doesn't want to cut fuel on deccel completely, sometimes AFRs are around 19 while coasting in gear and I occasionally hear pops and bangs from the exhaust.. Nothing changed on the car apart from injectors and fuel scale+map.. When engine switched off, pressure seems to stay for a while in the rail which kind of helps me to rule out leaking injector unless the leak is intermittent... Or maybe some seal got damaged during install and leaks only in high vacuum.. Don't know.. So, I want to change fuel pump and try 850s back on...
So, I wasn't really happy with those pops and bangs out of nowhere and really wanted to check if 850cc injectors will work fine with new fuel pump, so I swapped them back. Used 0.55 for injectors scale and tried to use the same fuel map that was developing on 440s. It's now too rich on high load and too lean in low load areas, but the issue with acceleration enrichment and misfires after it is gone, it's completely fine now. Seems like 850cc are working fine with ESL. I tried changing scale down to 0.5 while fixing idle and car reacts to changes. I'll keep working on fuel map with this setup, but for now I identified problem with intercooler - IAT readings raise from 30 to 55+ quite fast on simple 3rd gear pull on 0.8 bar now... I removed shroud for slanted intercooler from the bonnet because it was interfering with V3-4 intercooler I have installed currently, and I believe this is not way to go. Need to make some custom ducting to seal intercooler with the hood scoop...
Car is doing fine and I kind of tuned it to a point when I get pretty close to my AFR targets up to 1 bar of boost...
Still rich and has plenty of fuel to be safe, but close..
There is still one major problem that I'm struggling to solve.
Here is part of the log when I cruise on highway on light throttle... It seems that car cuts fuel and WG duty when throttle is below 13% (in this example), so when I drive in light loads on steady RPM I can get in situations when it jumps on/off. This is what I tried to catch in this log fragment..
What can cause this? I can't find any settings like this in the software.
Fully closed my TPS reads 2.7 and at WOT - around 78, so 12..13 range is nowhere near the idle range.. I found that problem gets worse with higher RPMs, like if I try to reproduce this problem on highway speeds in lower gear it kicks on/off harder.
Any thoughts?
The problem was solved by adjusting TPS on it's mounting screws. Previous closed voltage was 0.39v, now 0.76.
Factory specs are 0.5 +/- 0.3. car reacts now on slightest pedal movement but also cuts fuel when off throttle perfectly.
Bad news - it affected fueling and my fuel table is now very rich... Adjusted maf scale to get it back and looks like it worked.
03 July 2019, 04:08 PM
ESL help needed
