another high idle problem

I have a 1989 ford f150 300. When it is cold out sometimes after driving a while my truck after shifting into neutral will idle around 2k or so. If I shut the truck off then start it back up it will idle fine. Which to me rules out a vacuum leak. I have cleaned the IAC valve but still no difference but this problem doesn't happen when its warm out only when cold.
Any help would be great.

jhondatech

check your tps sensor. Sometimes they stick and act funny, and sometimes they work ok., which means it could be going out intermittently