Originally Posted by
Mike@SolerEngr
That's great, Jason. I'll get back to you by email. I have something here for you guys to try.
Quick question for all. At the most basic level; what is the root command the ECM gives the throttle body when idling? I.e. desired TP%, or desired MAF, or perhaps desired ETC motor ducty cycle, IDK. There are different ways to get the same result, but one of them should be the driver and the others depend on it; correct?
Here's why we ask:
So far, we know that the idle target rpm's are being achieved, but under different conditions, with higher airflow resulting in negative timing. It is as if the ECM strategy is fixing TP% and if MAF is not on target it then uses timing to control rpm's.
We have a log on a Z06 M7 with cams and 2300SC, our TB1 idled at ~20 g/s @ 20%TP with negative timing, TB2 idled at ~12g/s @ 12%TP positive timing. Same TB geometries; same hot idle target rpms, what could make it desire such different airflow and TP%'s?