idle hunting...is this a problem..?

[shimysham]

i recently got my dsm and it runs great!.. but, every morning when i go to start it after it has all night to cool down the car starts idle hunting... the engine revs up and down between 1000 and 2000 rpm's continuesly for about 4 minutes or so until the engine warms up and then idles at a steady 500 and its good all day long... it just doesn't seem right to me.. and if it is a problem, how do i fix it? ...........thanks..

 

[mrb91gsx]

Possibly the Idle Air Control (IAC) valve

 

[shimysham]

ok.... so then if its the aic valve then where is it located and what do i do? i kinda lack knowledge of a dsm right now..... since i currently came from a honda theres a lot a different things im lookin at here... unless it could be something else?...... thanks

 

[mark95turbo]

There are alot of things that can cause bad idle on a DSM. It sounds to me thought that the throttlebody is dirty. Take it off and check it out and clean it, then block off the EGR if it already hasnt been. You can find how to do all of this on either www.vfaq.com or www.plymouthlaser.com. Also check the vfaq for idle surge to see some other bad idle causes.

http://www.dsm.org/how-tos/tttt/tttt3.html

 

[SpeedFreak03]

Sounds like your FIAV (fast idle air valve) is ####ed, it raises the idle until the car warms up, but it sounds like yours isn't keeping the throttle plate open steadily. I doubt its the IAC because then his idle would always be shitty, not just when it first starts up (when its cold). Give this a try: http://www.vallotton.com/fiavblockoff.asp

Raising the idle when the car is cold is a bad thing anyway, there is no side effects of removing the FIAV. Just make sure to let the car warm up when its cold. Also, that 500RPM idle is low, do this: http://www.vfaq.com/mods/BISS-1G.html it tells you how to adjust the idle to 750, where it should be. Good luck!