High rev all by itself??

[anthonyl]

Its about 5 degrees here in WI. I just noticed the high revs the other day after leaving the car out over night. It usually happens after let up on the throttle in 3rd, 4th, and 5th gear. The engine will rev up to about 5000 rpm by itself stay for awhile and then drop down. My first thought was that it might be a sticking throttle cable. However when I rev the engine when the car is standing still it doesnt happen. Could it still be a frozen throttle cable or something else that is way too cold? The car did not do this when I had it housed at my fathers garage. Would love any feed back.

[gldfshkpr]

Idle control valve comes to mind. It could be sticking.

Edit: Oops. Only happens while driving, not at idle. Sorry.

[anthonyl]

So the problem started when I put my donut on after I got a flat. funny thing is as soon as I put my regular wheel back on the reving went away. still havent had any problems with it.