OK I got a situation that I have never heard before. I have a TPI system on a 383 cid in my 82 corvette. the other day while driving to the office it started making a banging noise. I was able to make home. Opened the hood and the noise by this time was pretty load. At idle it is load, give it gas and it bangs load then goes away. AS long as your giving it gas it doesn't make any noise. At idle and steady speed it bangs. But the banging is not consistent with RPM. Its every now and then as if a spark plug wire is against the headers and shorting out every now and then. The sound is coming from the top part of the motor but towards the front. I pulled the valve covers and everything is tight, nothing broken or loose. I took a screwdriver and placed it on the throttle body and the noise seems to be coming from there. I've checked the distributor and its good. The coil is good. So the only thing that I think it can be is the IAC. Does this sound right?