Hi guys,

I recently replaced my lower intake manifold gaskets, with help from the many posts on this forum! That rear bracket is a real pain in neck! However, when cold idle is around 1500rpm, and when warm around 2k. My first guess was the upper gasket, so i gave it a good workover with carb cleaner while running to see if the rpm fluctuated, and nothing changed. I also read a few posts on here about that little valve (cant remember the name, is it IAVC?) that is located on top of the throttle body at a right angle. It was completely gunked in carbon, so i sprayed it down with carb cleaner, reinstalled, and still high idle. Any suggestions?????? I'm wondering if a hose somewhere along the line hasn't been reinstalled properly, but i haven't thrown the check engine light, mind you it hasn't flashed in a few years! Throttle position sensor?

Thanks for any help you can contribute, and to the many posters about changing those gaskets!

...that little valve (cant remember the name, is it IAVC?) that is located on top of the throttle body at a right angle...
G'day,

I think you are referring to the idle air control (IAC).

The steps in this post may help: http://www.itocuk.co.uk/forums/viewtopic.php?t=10080

Your thoughts about an air leak somewhere also have merit.

Think i have it fixed. Repeated the process with the IAC, drowned it with carb cleaner, pulled the ECM, unhooked the battery for about 15 mins, put all back together, and still same problem. Unplugged IAC, started and watched the rpms drop to about 800, climb to 1500 and rev up and down constantly. Plugged back in, turned engine off and on again, and now idles normally. However, took for a 15 min drive, and upon return, before shutting down, i noticed that idle had risen slightly to about 1000rpm. Does the IAC fail? Should i just buy a new one?