idle issue

[John]

Ever since i had the car it had this weird idling issue i just cant figure it out.. its just idles @ 800 and then here and there its drops down to 600 and back to 800 repeatedly for a few minutes then it idles normal then it will do it again after a minute or 2 but i never notice it while driving... I was wondering if its the Idle Air Bypass Sensor?
and one more thing recently i have been noticing a sudden DRASTIC drop in RPM's when on the gas for a second then it all of a sudden comes back
CPS sensor ? thats what i was guessing it was..
Thanks for the helps ,

John

 

[projectSHO89]

Sounds like the IAC/IAB valve is sticky.

Steve

 

[John]

IAC/IAB valve what is the actual name lol damn abbreviations
and one more thing i had forgot to add.. also when i shut my car off i hear a PSSSSss. in the engine compartment.. anybody know what this is? Small Vacum leak ??

 

[John]

oh and is the IAC/IAB valve for the idle problem or the RPM Drop ? i was pretty sure that u guys would say it was a CPS sensor (For the RPM Drop problem....

Thanks,
John

 

[John]

Anyone ????

 

[93nighthawk]

oh and is the IAC/IAB valve for the idle problem or the RPM Drop ? i was pretty sure that u guys would say it was a CPS sensor (For the RPM Drop problem....

Thanks,
John

Idle Air Control Valve. It is located opossite of the throttle body. They tend to get dirty which cause idle and RPM problems, you can try to clean it or replace it.

 

[fastsho92]

change the IAC, my car did the same thing. my car when you hit the gas and then let it come back down to idle it would dip really low and some times stall. If it didn't stall it would dip down and then come back up to like 800rpms and then move around like it had a really big cam in it but it didn't. i changed the IAC and it did the trick. it is a little be hard to change it is really easy with the intake mani off but is you can do it by loosing all the intake mani bolts and lift up the one side.

 

[SHOmethe$$]

I have almost the same issue, I replaced the IAB, still does it. Any ideas? Plugs/Wires are new. Runs great normal driving, it is when I come to a stop and engage the clutch, the idle drops down, sometimes stalls...

 

[93nighthawk]

Did you re-set the computer after replacing the IAB? If not that is your problem.

 

[AutoSHO]

The hiss after you shut it off is normal when you have an open intake.