I have kind of a wierd idle. I think there is a vacum leak somewhere. How can I check for a vacum leak? My guess is that it is around my TB because I just switched it out and I had to reuse the gasket and I am missing 1 screw in the bottom to attach the TB to the IM. Second, whenever I let off the gas and begin to brake, my rpms drop, stop at 2k, hold steady at 2k rpms, and then drops to the normal point. My question is why does it does it hesitate at 2k rpms?
Thanks

 

I've got the exact same problem after I took my TB off cleaned it and adjusted the throttle stop screw.. I've checked everything over and the only thing I have yet to check is the TPS sensor.. bump for any other insight..

 

i sorta had the same problem in my jdm b16 when i'd put the car into neutral it would rev up the 3000 rpms and hold there, sorta like i was in cruise control then i'd have to tap the gas and it would go to idle, plus i had a wickedly high idle, i thought it was something to do with the throttle body to so i cleaned it out and everything, but it still did it, so then i finally found out i needed a whole new distributor cause it had gone bad, so that may be ur problem but chances are not, just giving u some options...