my 78 280z idles good when i turn it on, but once i tap the gas it shoots up and stays there.it never had this problem, it all started when i had it still for about two weeks. and know it smokes a little too, and that also started happening. I NEED HELP FAST.

Does the throttle itself stick, or is does the throttle return and the rpm's don't come back down? If the throttle returns, a guess is that the flap inside the AFM is getting stuck (staying open) and needs to be cleaned.