HI,
I have done a 2016 lt1/8l90e swap in a 66 chevelle. The motor and trans are stock with holley exhaust manifolds. it has a retro tanks and zl1 fuel pump in tank.
my problem when it switches to closed loop the ltft drops to -30% while the o2s are staying in the leaner area. it has a new maf, map, hpfp, oxygen sensors are new but not a factory sensor.
the tcm and ccm are new (with a gm dealer tune). the reason so many new parts is the drop out was from a wrecked donor.
I am also seeing -4 timing at idle. I am at a loss on what is causing this. the car struggles to runs and when in gear just crawls. watching the scanner the fuel rail pressure sensor reads 2000 psi at idle and then drops pressure as I am able to rev it.
The tune is factory with vats and other emission codes tuned off, but some still come back when scanning for codes.
here is my tune and log file. 3/4 way through the log file I reset the fuel trims.
Thanks for any help