i have a 88 IROC 305 TPI, 5 speed, totally stock internal, stock heads/cam. I have edelbrock headers, no cat, edelbrock cat back, 52 mm tb, edelbrock runners and base plate with port matched plenum, 24 lb/hr SVO injectors, ATI procharger P600 running 12 psi. I'm still using stock programming for the PCM, because i don't know enough about burning my own chip.

My question is.......what PSI should my fuel pressure be at, at idle? the car blows black smoke when i "get on it" my fuel pressure right now is at 36 psi at idle should it be lower?......should i turn the FMU down a 1/4 or a 1/2 turn to lean it out a little also?

thanks in advance

 

Well I think that is your problem only 36psi with a super charger...I run 50psi on my 350 TPI with headers and some porting and polishing. I'm not to familiar with turbos and superchargers but I would think you need more pressure for sure. Wait a bit and someone with a bit more knowledge will answer this for you , but I I do think that is your probelm your leaning out. Also with a 52mm TB and 24# injectors you should really get that chip burned to your application. The ECM is confused right now and I think you may be hurtin your internals with the way you have it setup.

 

I think your best bet would be to have your car dyno tuned. Find a dyno where they hook up an air/fuel ratio gauge. This way you can have your car tuned for power and safety. All cars react differently so it's hard to say where your fuel pressure should be set at. Plus you get to find out what kind of power your putting out.

 

I've already had the car dynoed, but not with a wideband air/fuel reading........if you were curious.....391 hp and 422 ft lb to the wheels.