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It will affect cruise. So if it does fix the issue but now cruise is rich how would i fix rich cruise without touching the ve map?
*note: finally got around to reading the thread you posted...jhon bradley says should richen up 99kpa area...some dude did it and said it worked...gotta try it out i guess and see how it affects everything else...
Last edited by nor11384; Jul 18, 2018 at 09:12 PM.
Change your MAP VE to what it was and
Change your RPM VE from 1250 - 2000 to 95 .
See if it runs better,
Slowly increase 40~90 Kpa load values , These values seem low.
Well injectors are stock. I thought taking fuel from rpm ve was essentially the same thing? I will defenetly try it. Also, I though the right side of the column shouldn’t be greater than kpa side. I always thought it should be no more than 1:1.
I don’t monkey around much with running closed loop, not sure why the afr map wouldn’t work. I would try lowering the AFR map in the 60~100 load range, zero to 2000 rpm and see if that makes a difference. This way other areas you have tuned previously would not be affected.
I don’t monkey around much with running closed loop, not sure why the afr map wouldn’t work. I would try lowering the AFR map in the 60~100 load range, zero to 2000 rpm and see if that makes a difference.
The ECU doesn't refer to the fuel map when running it closed loop.
The ECU doesn't refer to the fuel map when running it closed loop.
Ok thanks Raptord, I do remember now I think I turned messed with the thresholds to get the fuel map to work now that I’m thinking about it. I was thinking the fuel map in addition to the fuel trims is what gave us our fuel pulse width. Most big injector cars we just run in open loop and it works just fine. Closed loop is for emissions compliant vehicles IMO.
I have never seen a SD VE map table with higher values in the % column below 100kpa. Not to say it wouldn’t work tho.
Gotta do what it takes to get the car to drive well. The Stock ECU SD shouldn't even work, so there's that... It's all trickery and funny business to get the stock ECU to do what we get it to do, so tuning one means you can't approach it as "normal".
Originally Posted by Raptord
The ECU doesn't refer to the fuel map when running it closed loop.
Originally Posted by 2winscroll
Ok thanks Raptord, I do remember now I think I turned messed with the thresholds to get the fuel map to work now that I’m thinking about it. I was thinking the fuel map in addition to the fuel trims is what gave us our fuel pulse width. Most big injector cars we just run in open loop and it works just fine. Closed loop is for emissions compliant vehicles IMO.
Fuel table is open loop only. Closed loop is not necessarily only for emissions compliant vehicles. It's for having the desired AFR at a given RPM and load. This limits the stock ECU because it only has a narrow-band O2 sensor, so we typically have it go into open loop in the 0-2psi range. But aftermarket EMS's and even a lot of modern OEM's run full time closed loop with wideband O2 sensors. If I could afford an EMS (like an infinity), it would run full time closed loop.
Very interesting. Learning a lot. Haven’t been able to try it on the car yet. It’s in Jack stands waiting for me to finish the ic pipes but it’s storming here every day. I will post results after I monkey around with it a bit.
Gotta do what it takes to get the car to drive well. The Stock ECU SD shouldn't even work, so there's that... It's all trickery and funny business to get the stock ECU to do what we get it to do, so tuning one means you can't approach it as "normal".
Fuel table is open loop only. Closed loop is not necessarily only for emissions compliant vehicles. It's for having the desired AFR at a given RPM and load. This limits the stock ECU because it only has a narrow-band O2 sensor, so we typically have it go into open loop in the 0-2psi range. But aftermarket EMS's and even a lot of modern OEM's run full time closed loop with wideband O2 sensors. If I could afford an EMS (like an infinity), it would run full time closed loop.
yea I had a Cobalt SS lnf 2.0 I tuned. It had a wideband from the factory. Pretty much fuel tuning was done by itself. I understand with the varying levels of ethanol in the fuel you could cause slight differences in afr.
Our evo’s don’t have a wideband to control the ecu and I have no problems getting consistent afr’s in open loop, therefore I’m not concerned about running in closed loop.
Another way to fix your issue would be to log your maf hz and see what frequency your hiccup is occurring at. Then bump up the percentage numbers at that particular hz. Problem with doing that it might affect afr’s at higher rpm’s and light throttle position. But you could see if it helps.
Ok so i tried what you guys said and it didnt work. In fact, it made it worse. In first picture you can see how much i jacked 50 - 90 kpa. The weird thing was, when cruising the afrs were pretty stoich. I was expecting to see them go way rich. I think somehow this change had no affect on afr or something was going on. Now, when i made this change the car started choking when taking off in 1st gear worse than ever. It would go way lean and you could only see --- on the gauge and felt like i was hitting a wall. I had to clutch in, rev the rpms, and go. Now, i made an observation. When this happened i stopped at a gas station to analyze things and car kept trying to die because it was going rich (11s). Also i noticed iat temp was at 100 or so and coolant temp 203. This seemed to be when it was doing it worse. So i loaded up the previous map and made some changes to async vs tps delta and accel enrich base vs engine temp as you can see in second pic. What i saw happen when change accel enrich was when changing gears it would no longer stay full lean for a second or 2. Now i would change gears and it would bounce off lean and come right back up to where its supposed to be. Taking off in first seems way better too. By this time it was night time and iat was in the 80s and coolant temp 195 - 200. I would like you guys' help with something else that has been happening. Say im cruising along and coming to a light so i throw it in neutral and coast to a stop. The afrs will stay around 16 - 17 ish for a bit and engine slow down like when it tries to die before it comes up to regular idle afr (14.5 - 15). Also say car is idling and i turn it off to lets just say flash it or whatever. When i try to start it again i have to give it gas because it will try to die. Not all of the time but most of the time. Seems to happen most when really warm. Sorry for the long post guys just wanted to explain everything. Still need to go out and test some more.
Nor, the issue with the car going lean when you let off the gas will always be there because of fuel cut on deceleration.
The second issue with the rpm’s dropping low and car sometimes dies is usually biss screw adjustment and/or idle step position lookup related. Very similar to throttle hang issues just things are backwards. What I do is log your idle step position and see what it’s doing. In the base step position table you want it to read about the same as it does when it’s actually idling warmed up with the a/c off. Get it idling with the same steps as you have in the lookup table and I bet your issue goes away. If it’s only when the a/c is running then you need to change that table.
