Hey guys,

Having a few issues with the final parts of the tuning. Biggest issue is cranking/starting. It really sounds like i have way too much fuel when cranking but am unsure what to change. I have started with the 2002 Express van tune for the 5.7L Vortec engine and have made changes to accommodate for the bolt-ons i have installed. I have tried using maps from LS based engine for VE when cranking and commanded fuel when cranking with no good luck.

383 internal balance
Mercruiser MPFI ported, 27lb injectors EV6, ported throttle body
Iron 64cc vortec ported and polished
Comp Cams Beehive springs for 0.550 lift, Crane gold rockers 1.5 Camshaft:Comp Cams XFI 280 hydraulic roller, Comp Cams Magnum hydraulic rollers
No cats, 1 7/8" long tubes, Custom 3" CAI

Cam specs:
Operating Range: 2000-6000 RPM
Duration Advertised: 280° Intake / 288° Exhaust
Duration @ .050'' Lift: 230° Intake / 236° Exhaust
Valve Lift w/1.6 Rockers: .576'' Intake / .570'' Exhaust
Lobe Separation Angle: 113°


Idle spikes between 500-1500 rpm during the first few minutes of running. Usually smooths out when temperature hits 100F or so. After that, AFR is dialed in at 14.7 and timing is nice and smooth.

Last issue is i can not hit 12.2 Commanded AFR not matter what i do! Somewhere i am missing something that involves a multiplier or such but cant find it no matter how many threads i read.

Xtreme_APRIL 21.tun