I have a 94 camaro lt1. Car runs ok cold but after driving it a few miles runs like crap. Misses like crazy on WOT. Idles like crap after that. During WOT I see a lot of black smoke out the tail I guess telling me its running rich? I just put in a walbro 255 fuel pump - no other mods to the car at all. I checked the fuel pressure - ok - around 40 psi. Vaccuum good - around the same. I tested the fuel regulator - ok. I unplugged the maf and map sensors and it runs even worse in open loop (I believe unplugging these does that). I replaced the coolant temperature sensor in the water pump as well. Any ideas? Could this be the optispark?

 

If I were in your situation the first thing I would do it scan it for codes. Have you done that yet?

 

Could need plugs and wires. When it's good and dark, start it up, open the hood, and see if you can spot any arcing around the plugs, wires, and coil.

 

Sounds like heat screwing with the ICM or coil to me.

 

check where your intake meets your TB. I know mine had a rip in the 90 degree elbow near the TB and caused my car to run like crap cause it was sucking way too much air. Dont know if that will help but just throwin out ideas to help you.

 

when was the last time you did the opti and plugs, mine ran like crap when the opti went south.

 

Have the o2 sensors ever been replaced?