Hey everyone... For the past my car has been idling at around 1250 rpms and all the way up to 1900 rpm when the car starts... after a while it goes back down to 1000-1100, but whats up? anyone? I searched, but dont think I knew what I was searching for

first you should check to see if a vaccum hose came off or if one is damaged/cracked in the bay. That would definatly cause a high idle.
Do any under the hood stuff lately ?

wouldn't it do that to warm the car up? idk that's what mine does...didn't think it was such a big deal since it does fall to normal idle when it warms up

1900 seems kinda high for a warm up usually 1200-1400 then a 900 idle for the st I think. anyone else agree with this?

mine idles at 1800 or so on a cold day until the oxygen sensor heats up then it returns to normal idle at 800.
-Aaron-

This post has been edited by afroman: Oct 27, 2005 - 12:53 AM

-dustin15brown+Oct 26, 2005 - 9:31 PM

idle speed should be 700rpm for 96 mt st, the IAC (idle air control valve) could be faulty. remember that idle speed varies depending on electric load. turn off all electric accessories and see if it is still idling high. if so disconnect IAC and check for proper resistance between terminals. for 96 the accepted range is 17-24.5 ohms.

Mine idles at 500-700 once it is warmed up.

It could be a cold start idle,mine only goes around 1400, but every area will be dif, and the number of miles could alos change it a bit.