High Idle RPMS!!! Please help. DSM GURU's please read.

[dyno_detour]

When I first start my car up, the tach reads around 900-1100 Rpms. After the engine reaches normal operating temperature the engine revs around 2500. Sometimes even 2900!! Anyway, why does my idle surge after my car is warm? Second, is it really hard on the motor to idle at such high Rpms at a stop light?

Thanks for any advice,
Ryan

 

[billys90tsi]

One thing i would do is wait for you car to get to normal operating temp and adjust your cas or adjust ## idle screw.

 

[dyno_detour]

After my car cooled down, I screwed in my BISS (base idle set screw) completely, then 180* and the same thing is happening. Thanks for any help.

 

[zippyshoe]

These sound like symptoms of a possible faulty IAC (Idle Air Control) motor. Here is a link which provides info on testing your IAC: http://www.dsmtuners.com/forums/showthread.php?t=217402&highlight=IAC. Hope this helps!

 

[Black91TSiAWD]

Mine does that sometimes(idle at 2k), Ive been battling it since I bought the car, Ive ruled it down to a bad ISCS(idle speed control sensor), and theres the FIAV(fast idle air valve) that can go bad too, just diagnosing it can be a pain. But what I do is I just have the car running at normal warm temp and turn the BISS all the way in then work it back out enough until she settles somewhere reasonable. I only have to mess with it every couple months, but it has a mind of its own when it wants to do it, cold, warm, hot, just doesnt matter.


Idling at a redlight that high isnt bad for it, just wastes more gas. Think about how long she stays at 3400+ on the highway for.

 

[dyno_detour]

Thanks for the advice Black91TSiAWD.

I just thought it might be hotter on the engine at a stoplight since there is significantly less airflow as opposed to the interstate.

 

[Black91TSiAWD]

Yeah but for the amount of time youre there, it wont make a difference.

 

[4BangR-x]

hey at least your car idles