1987 iroc z z28 tpi, wont idle right, runs rough/stalls untill about 1800 rpm runs great. Plugs all looked the same, i dont think its a stuck injector. Replaced 02 sensor, ign coil, wires, plugs, fuel pressure 30, unplugged mass airflow sensor, runs the same, any suggestions?

 

IAC is all gunked up or the EGR valve is not sealing.

 

Egr is good, the idle seems better, but it stumbles real bad if i push on the throttle hard, its hard to accelarate, could that still possibly be the iac?

 

How do you know the EGR is good? A stumbling on accelerartion can be another indicator of a weak EGR spring. "Idle seem better" did you do something?

Check engine light?