I posted earlier about my 1985 corvette. Got it running, put a computer in it, runs ok when hot but to start it cold you have to pump the accelerator until it warms up then it will idle, but as soon as you get down on the throttle it pops loud through the fresh air intake. No trouble codes. I think it is the EGR, with vacuum it wasn't opening. Please advise!

 

EGR not opening will not cause that problem. Your problem sounds like a vacuum leak, dirty injectors, or Mass Air Flow sensor. It's hard to tell from the brief description and with out watching scan tool data. Try unplugging MAF and see if problem changes to the betterment of your problem. It will set a code, but you can clear that out. Have you checked fuel pressure? [8D]

 

thanks mech259, I have correct fuel pressure, and ultrasonic cleaned the injectors. The poping sound is intermittent when you get on the throttle, sometimes if you accelerate real slow its like it gets past it then sounds fine. Right before it pops it has a dead spot in the throttle .Hope this is a better description.

 

Well, next thing to check is a tune. Misfiring plugs will sound like that too, along with cap, rotor, wires. Use some good quality wires and plugs. [8D]