ok so it's not a J-Body, but a close cousin. It's a grand am with the 2.4 and it idles around 3000 rpm. There are no vacuum leaks. I have replaced the MAP sensor, Throttle body with all sensors, battery, alternator, and half a dozen other things. It will start up around normal rpm for a few seconds then work it's way up to around 3000 rpm for about a minute, then go back and forth from 3000 to around 1000 for about a second each. I have the car sold and now have to make it run right. Please help.

does it have the egr valve? if so have u checked it? my buddies saturn had the same problem and it was the egr valve

found it. its' a broken wire below the idle air control valve.