L86 8L90 swap very rough idle and surging

[blackdog76]

I have the following hardware installed for an L86 8L90 swap into a 67 Camaro.

L86 with: LT2 intake, Spectre CAI from 2016 SS Camaro, Speed Engineering (short) headers, 3" exhaust with X pipe
8L90 stock
Fuel System: Aeromotive 340 in tank pump, 30-90 adjustable fuel pressure regulator controlled by relay from FPCM signal wire

Lots of surging at idle and boggs down really low at times. When throttle is depressed, RPMs hang at 2500-3000 and stay there before eventually going back down.

I noticed that in the fuel system in my tune, FPCM is selected which doesnt seem right. Anything else Im missing that is off with the base tune, the tuner did for me?

camaro tune.hpt

[blackdog76]

I have the following hardware installed for an L86 8L90 swap into a 67 Camaro.

L86 with: LT2 intake, Spectre CAI from 2016 SS Camaro, Speed Engineering (short) headers, 3" exhaust with X pipe
8L90 stock
Fuel System: Aeromotive 340 in tank pump, 30-90 adjustable fuel pressure regulator controlled by relay from FPCM signal wire

Lots of surging at idle and boggs down really low at times. When throttle is depressed, RPMs hang at 2500-3000 and stay there before eventually going back down.

I noticed that in the fuel system in my tune, FPCM is selected which doesnt seem right. Anything else Im missing that is off with the base tune, the tuner did for me?

camaro tune.hpt

Log File

log 2.13.hpl

[GHuggins]

Change fpcm setting and see if timing comes back positive. Only thing I looked at so may have a lot of other things wrong causing the very negative timing and incorrect fueling.

[blackdog76]

Change fpcm setting and see if timing comes back positive. Only thing I looked at so may have a lot of other things wrong causing the very negative timing and incorrect fueling.

will do, thanks

[blackdog76]

I did an idle clean and reset the fuel trims. Runs great now and no more hanging rpms.