I have a 1989 Camaro IROC 5.7, no mods to engine, the car had sat for about a month without starting, got it registered and found it has a really bad idle, also seams to have lost power, took the car to a local mechanic, he hooked it up to his scan tool and found the car was running rich. I thought the car might have some carbon buildup or sludge in the throttle body, removed throttle body and cleaned it thouroughly, no change. Took of and replaced the IAC for $70 no change tried running techron through no change, diconnected maf, sprayed the whole intake/vaccum system, replaced the gasket between the throttle body and the plenum, nothing worked... PLEASE HELP... she has 88,000 miles, and some mods here and there, im just so lost

 

Check your fuel pressure regulator.

 

Also check your timing.

 

You're just throwing parts at it. Time for the basics. Check the fuel pressure, plugs, and wires. Make sure all the injectors are firing. Check timing and vacuum. A fouled plug, bad wire, bad injector, and a dozen other things could be the cause.

 

I assume you're not getting any codes?

In addition to all the above mentioned, make sure your TPS is set correctly.