All;
We are tuning a 04 GTO LS1 with a larger cam installed. I setup the Auto VE file and loaded into the car. I noticed that the idle is between 65 and 70 KPA...Seems high (low vacuum?), so we verified the sensor and checked for vacuum leaks. So far nothing has been found.
I also noticed that the commanded AFR sitting at idle (800 RPM) is jumping between 12.9 and 14.64 AFR. It seems as if when the MAP sensor is reading 68 KPA or higher, the commanded AFR is going to 12.9 and when it is less then 68 KPA it is reading 14.64. I check my close loop AFR table and it is set to 14.64
SO I have two questions....
1. Is there a setting somewhere for minimum vacuum at idle that would be changing my commanded afr? Where is the 12.9 coming from?????
2. Even for a larger cam (I don't have the specs currently), does 65 to 70 KPA seem too low? Should I be looking for vacuum leaks somewhere?
Thanks!