I have an H22 in my prelude. when i am driving the car is fine but when i press the clutch in and put it in nuetral the revs bounce from 800 to 1200. it use to only bounce 3 or 4 times and then stay at 1100 which has been my idle lately. now it keeps bouncin no matter how long it sits. any ideas?

 

its your FITV the peace under your throttle body remove your t/b remove the bottom peace will have two nipples that runs coolant lines to them. it is attached to the t/b by 3 screws. once you remove it it has two plate sides that you can take off. one of them will have a big white "thing" screw that on tight again with a flat head gripping it from one side. they say to give it a little touch back once you make it tight. but uhhh my friend in like 2 months your gonna have the same problem. if you dont live in really cold weather i say you block this thing off. do some searching and youll see what i mean.


if your lucky it might just be a vacum leak. make sure all your vacum hoses are connected and none are cracked.

 

It could also be a bad intake manifold gasket. Get a can of carb cleaner and spray where the intake meets the head while the motor is running. If it idles up or if it tries to die, your intake gasket is bad. Also, make sure no one has messed with your throttle cable. Make sure the butterfly is closing all the way. You should be able to move the cable up and down maybe 1/4 inch without it opening the throttle.

 

could be a number of things...fast idle valve which is what royalfelix described. also is the car throwing any codes? i know i just delt with the problem! but first off check around the throttle body and intake manifold for a lose vaccum line or a cracked line...that can cause your idle problem!! goodluck with the problem man!! oh yeah!!! if it keeps bouncing non stop when you are in nuetral or have the clutch in it could be the IACV!!! that can be cleaned very carefully though

 

idle air control valve maybe