on the back side of your intake manifold the part that is facing the fire wall it should be a eiac valve it has 2 coolent lines going to it and a eletrical plug undo the two 12mm bolts take it off and clean the hell out of it with brake clean , throttle cleaner, parts cleaner, wut ever you can get your hands on it should take care of the surging if not it will make it alot better and if it only makes it better and doesnt fix it then replace it