Recently my idle got a little wired. When I start the car the it idles at around 3k for a couple mins, then falls down to 2k then a min later falls to 1.5k and stays there. after i drive for a couple mins it falls down to around 1.2k. My normal idle was always at 900. this has been happening for about a week or so. what could be causing this problem??

thanks!

 

any ideas?

 

what gen car, what motor, is there any cel?

 

its a 5th gen prelude, built turbo h22. no cel

 

Could be a FITV (fast idle thermo valve) problem. First, make sure your coolant is bled properly. Other than that you may need to tighten up the plastic screw inside the FITV body. That would be my first guess, otherwise it could be the IACV.

 

also check the tension on the throttle cable, happened to me. random idle was bugging the hell out of me, realised the cable was a lil too tight. now my h22a-t idles @ 800 and purrs just fine.

 

sorry to bump an older thread, but I'm having this EXACT problem! My idle screw is in all the way, no CEL. I cleaned the IACV and the FITV... any other suggestions? My idle screw is scored at the end of it, and the o-ring is a bit worn, could this be the problem?

Powerdbygarrett, did you end up fixing this problem? What was it?

Thanks guys,

Mike.

 

No man i actually didnt, i did the same exact steps u did and nothing worked. im still stumped at whats going on??

 

ahh, i know its soo annoying. I'm gonna try bleeding the coolant tomorrow and replacing the idle air screw.

Have you tried bleeding yet?

 

bled the coolant... didnt do ANYTHING! Hopefully I bled it properly... whats the proper way of doing this? Is it supposed to have a continuous flow when the screw is open? Why does my coolant resevoir keep bubbling! I wonder if theres more air...

 

I FIXED IT!!

Powerdbygarret, check your FITV, open it up and tighten that one 'cream' colored spring loaded thing in it! tighten it down all the way. this fixed my problem, it idles perfect now! =D

 

aight man i checked my FITV again and tightend that cream color spring thing, hopefully it will fix it, i cant really check cause as bad as it sounds, my parents are sleeping and if i start my car they will kill me... gues we will find out tomm
i'll let u know!

 

IT WAS THE FITV!! idle is back to perfect now! thanks everyone