I have a 1993 gxe and everytime i put it in park it surges (goes up to 2k rpm then drops on its face repeatedly) sometimes it only does it once or twice but other times it keeps doing it until i put it in drive then it drops on its face again and its fine after that i recently cleaned the upper and lower intake, egr valve, and throttle body, and replaced fuel injectors and air filter and fuel filter to try to fix it but nothing has helped

 

Man it could be tons of things. You have to do a couple of test. But if only happens at idle and it drive fine when your foot is on gas pedal then I would look for vacuum leak.

 

it only does it when in park any other time it is fine i could be at a stop light and it would be fine but if i put it in park it starts surging

 

Have you tried cleaning the iacv aswell?

 

i was thinking about that but it idles fine except in park