I have an 1989 GTA, 5.7L, auto, running rich enough that after lettting it idle for about 10 miniuets three or four times, while I'm trying to figure out the problem, the plugs are so fouled it won't start and I have to change them. I replaced the computer, MAF, oxygen sensor, and thermostat sensor. I also used a Snap-On diagnostic machine to check the IAC, TPS and every other sensor I could. Diagnostic show everthing working properly and I even have proper fuel pressure. I have no experience with TPI and am completely stumped. Any help/advice would be greatly appreciated.

 

Well heck, welcome to thirdgen.org!!!

I'd have to ask if the scanner shows the rich condition or not?

From what you describe, sure sounds like fuel is dumping in way too fast for normal diag.

May want to pull the vacuum line at the fuel pressure regulator and smell for gas, could be it;s ruptured and needs replacing.

Check the crankcase for fuel? best to do first to be sure you're not working on a potential bomb...hate to see shrapnel blow though a body...eyyuuuck!!!