Hi all!
First let me just say that I'm a recent user of this forum and in tuning Vems ECU's.
I have experience in tuning Megasquirt ECU's.
I'm tuning a friend's Citroen boosted Saxo VTS with Vems ECU that he has bought from DP Engineering.
The ECU is a V3 and it has came with the firmware version 1.1.64.
I have managed to tune the idle, not perfect but acceptable, and the low kpas of the VE table and the car was drivable.
Then I decided to upgrade the firmware, because I read that the versions 1.1.6x wasn't that good.
I upgraded to version 1.1.70 and uploaded the config that I was using in version 1.1.64 and then the problems started.
Now the idle is very bad and the rpm very high, even if I lower the ignition to 5 degrees, close the IAC valve and with the AFR showing 15.5, the engine stil revs at +/- 2000 rpm and I can't lower it.
Also the car was very smooth when I hit the throttle and now is very weird and sometimes backfires a litle bit.
Another thing is that I think the coolant gauge is not showing the right temperature.
Don't understand what happend. I just upgraded the firmware.
Can someone explain what I'm doing wrong or what's happening?
Thanks in advance.
I think I've managed to watch your 1.1.96 config. I had broken VT installation on my job PC.
I can't find somewhat wrong comparing to your 1.1.6x one.
But anyway - there is some issues:
As I mention - required fuel. Some enrichment values is scaling of required fuel: cranking, warmup, acceleration...
I suggest to check ignition timing. Because 1.1.6x was not officially supported f/w.
My suggestion is also switch to "simplified" injector lag compensation and write there some reasonable values. Better - find real ones.
EGO step size should be 1%. Cycles - usually 4...10. Speed limit 40...64. You can use closed loop also under boost if you have no undersized exhaust (pressure disturbs signal). You will find faster O2 sampling in 1.2.0 - migration here is easy comparing to your 1.1.6x->1.1.96 case.
MAP sensor range is 413 and offset 3...4.
Check wide band calibration.
Coolant and MAT temperatures. Here you can use patch files (tools->firmware->patch upload) or use own curve. Second option give more flexibility.
VE table is not tuned. And probably it will be very hard task with those cams. May be better to choose Alpha-N strategy with MAP compensation under boost. Best - change the cams. With correct required fuel you will not see there values higher than 120. If higher required - means defect: pump, pressure regulator, injecors 100% duty...
Igniton table generally is ok. load range is sufficient? Dragrace require much more boost!
MAP/TPS table is dangerous. In real life it is not so sloppy. You can import one from default configs and start from there.
Acceleration dtps map is terribly wrong. Small movement should mean little additional fuel.
Low rpms require more RPM acceleration values, high RPMs - less.
Stepper. Try in open loop (PID zeroed) - does stepper gives enough flow to change something. Most of correction will be upon to ignition.
Boost control. Do you use it?
Speed sensor?
SD card?
Gints