86 corvette coupe 350 engine, not the crossfire. when car starts to warm up to correct operating temp & stopped in traffic @ red light, etc the car starts to idle roughly and I have to throw car into neutral & give it gas to stop it from stalling. I have had the idle air control valve, throttle position sensor, gasket & rebuilt the throttle body and it still has the stalling issue. The RPMs drop and almost stalls until I put it in neutral and give it gas. It originally started happening when air conditioner was running but now it does all the time. Help!
Any check engine lights? How many miles on it? I assume it is an automatic (you don’t expressly say).
I’d say you have a vacuum leak somewhere. Go “old school” and attach a vacuum gauge on the engine and get a reading while it is running. I’d bet it is low and erratic. You can hunt for the leak “old school” as well by using propane to find the leak. When it is close, the engine will smooth out. You have a lot of 33 year old dried-out rubber hoses and gaskets to check. Good Luck