Im sure there have been a billion and a half threads on this exact issue, but ive gone over just about every single one and have not found a solution. Truck is an 04 tahoe with a stock 5.3 and electronic throttle body. Owner did a ls1 "hot cam" swap which includes springs. he installed the springs and cam and asked for me to lend him a hand tuning it.
Here is what ive done so far, the engine will not idle whatsoever below 2k rpms, in fact i have not been able to successfully get the engine to idle without assistance from my foot on the accelerator whatsoever. Adjusting the baseline airflow from 6g/s all the way up to 64 in 2g/s increments has not shown any benefits other than better top end response. Engine will not start without pressing the throttle about halfway and will fall on its face below 1500 and will only attempt to stabilize at around 300 rpm. This tune is all over the place because i was trying multiple things to see what would help it, i havent found anything yet that would solve the idle issue. Adjusting the VE from 80-100 kpa below 1200 rpm helps slightly, but doesnt solve the issue. im also getting maf errors, but adjusting the delta seemed to fix that. is it possible this cam is simply too large for the 5.3 to idle at 800 rpm?
Any help is greatly appreciated. jeffs log file.hpl5.3 modified tune 2.hptIMG_E0310.jpg