ok, was datalogging tonight, and saw my timing advance is trying to go to like 35-40 degrees advance at light constant throttle around 3000rpm no load. if i hold it there i will get a po300 code within about 3 seconds and can definately hear it misfiring right before i get the code. i am pulling most of my 660cc injectors via the airflow map, but am pulling -40% and it is not showing a true 40% reduction in the datalog. it have finally found a sweet spot for my idle being at 1.9ms.
any ideas why the car is trying to advance so much? if i get it figured my car will truely run great!! thanks

 

Because you are scaling so much via maf it is reading less air and puting you at a place on the map where the timing is more advanced.

 

35 to 40 degrees of timing at cruising throttle is perfectly safe, normal, and clean, as their is minimal load on the motor.

 

i heard that it was safe to pull that much maf signal and that only scaling down in the injector map that much could possibly effect timing.

 

i kinda figured as much at just a no load, but it does seem to work some what in unison with the car throwing up a po300 code. if there is no load it will start to misfire if i hold the throttle steady, but with the car driving it will begin to stumble after a few seconds of holding the throttle steady and a/f will go either full rich or full lean at the same time. if i keep letting off and getting back on the throttle all the time it will run great. just sounds like i don't know how to drive and makes me dizzy, hahahha.

 

Are you seeing boost when this occurs?

 

nope still in vacuum. during accell under boost it is fine. just leaving the throttle in one position for more than a few seconds triggers it