how long should the "fast idle" last on a cold start.

i live in Florida and some mornings when its down to say 65 or so on a cold day here the civic wile fast idle around 2200 2300 for like 3 min strait it wont come down to a normal idle for over 5 min sometimes. but then when it does its fine for the rest of the day. also as its dropping to normal idle speed its wavy it dosnt drop smooth and gradually

if its normal outside like 80 it still stays up there for a wile unless i drive around.


just wondering if there was a reason it stays so high for so long every other car i own only does it for say 1 min maby then down and down quickly.

 

Search for cleaning fitv. It's in the faq as well. It will answer this question.

after cleaning the fitv and iacv then look for vacuum leaks

 

This piece is mechanical and I do believe goes off of coolant temperature, closes off around 100 degrees F. If it is staying open, you may need to adjust it or replace it (process can be found in the FAQ)