hey guys just having some problems with the car finding where it should idle. if i start it up and sit in my driveway its fine. i can go out for a ride, and when i stop at a light or something it starts to surge, so if i put my foot on the gas to like 2000rpm then slowly lower it to 900 it will stay at the 900 and idle fine. as soon as i rev it again, i have to lower with the pedal otherwise it just surges. any ideas? possibly IAC, it is a new one. thanks

 

vacuum leak of some sort, possibly upper intake gasket.

 

ive had it apart 3 times now, and im pretty sure its sealed up fine, i can spray around it and get no change in idle. im going to be be taking the upper back off tomorrow, ill check it again.