90 integra b18a1 only mods is intake and exhuast. Started out reving between 1000 and 2000 rpms until it got warm then smoothed out. Then started doing it all the time. So I replaced the IAC valve and it started running at 2500 rpms all the time so I took the new IAC valve off cleaned the old one with a whole can of brake clean let dry. Reinstalled old IAC valve. Now im getting te same thing as it did with the new one until I let the car sit for about 15 min and started back up and now I'm reving between 1000 and 1500 rpms. Reinstalled new IAC valve and no change. Reinstalled old one. I thinking the fast idle valve is screwed up but I was wondering if the fast idle valve would make the rpms jump like that or just make the car idle high? Thanks for any help!

 

Oh yea all vacum lines have checked and are ok

 

Never mind guys I just found the fast idle valve thread. Sorry must have over looked earlier. Thanks anyways.