Well my 94Z is having issues starting, and it missfires like crazy, from low rpms, to high. I replaced the plugs,wires, opti, coil. I am thinking my last resort is going to be the O2 sensor's. THe car is throwing no codes at all. When I first start it, i have to hold the throttle up to about 4k for about 10 seconds, it clears out, then it will idle. If not, It will just die, and take forever to start again. The 02's are my last resort. The engine is a rebuilt 355 LT1, with the hotcam kit, edelbrock headers, borla exhaust. Any ideas? Thanks

 

are you getting enough fuel?

 

I am gonna check the the fuel pressure next, any ideas what it should be at? Idle, WOT?

The thing about that is, its running so rich, its blowing dark smoke out until it clears out..

 

could it be that cold start BS? When your water temp(coolant) is below 100, your computer dumps extra fuel in to warm up the car, maybe it has somthing to do with that?

Or maybe try cleaning your IAT & MAF sensor's. That happened to me once, MAF was f-ed up and I was running a lil rich for some reason...

 

anyone else?