So it all started with my fuel pump going out, which led to some interior upgrades and the addition of A/C, and now about 4 months later i'm finally able to get the car back on the road. I replaced my Pierburg pump with a Bosch 69607 external fuel pump. Once I got everything put back together, and started the car, it wouldn't hold an idle and would spit and sputter every time i hit the throttle. I've got my FPR set to about 52 psi. I have done nothing to the engine but change the FP and now the car won't run. I was getting some MAP sensor codes but after replacing the MAP, it's still running like crap. I thought I had a vacuum leak at the intake gasket because when i sprayed brake cleaner around the intake ports, it would idle up really fast and then go back down. So, after replacing those today, it's still not running right. In fact, if i give it too much gas, it backfires and pops. I know this is starting to sound like a bad opti but it was just replaced about 2 years ago and I can't see how sitting for a few months would cause it to go bad. The car ran great before my FP went out and i'm at a loss at trying to figure out the problem. I'm not against putting another opti in the car but i'm not a big fan of spending that much money just to see if it fixes the problem.

 

The map codes could have been related to the vacuum leak. Maybe after 4 months of sitting the opti was in a humid environment and built up rust internally but seems unlikely. If you have a MAF, try unplugging that and starting up the car. Try testing for leaky injectors by removing the fuel rail with injectors installed, prime the pump with engine off, and make sure none of them spray out fuel. Wouldn't think it would be O2's or temp sensors. Double check all electrical connectors, spark plug firing order.

 

We'll I got it figured out. After replacing the plugs, wires, opti, coolant temp, and map sensor it still ran the same. I then xferred the maf and iat from a known food car and still nothing. So, the only thing left to replace was the computer and when I swapped it from my other lt1, that fixed it. I put my computer in the other car and it ran like crap.

I have no idea how a computer can kind of bad. It started and idled and didn't throw any codes and I could scan it with my scan tool so I don't know what could have happened.

 

Glad to hear you got it working, I understand that it is unusual for the computer to go bad. If ever needed they sell computers that are car specific, IE LT1 camaro, corvette etc. on ebay for 150, I though I had to get one recently as my car was throwing codes when trying to pass DEQ/Smog, but turned out to be a burned out SES light bulb on dash on my 96, best wishes