Car Studders At Idle

[pecka]

On my 95 Talon TSI when I start it up first of all it idles at like 2100 rpms, then after a little bit it falls down and bounces from 1300 to 1600. After looking through my Chiltons manual I figured it could maybe be a PCV valve? What are your guyses thoughts on it?

 

[blackGSX2g]

maybe the IAC? Sometimes the motor in that goes bad and has trouble keeping idle the same.

 

[TurboAWDjunkie]

idle speed control motor .. $225 brand new from a dealer ... go jack one from a pick a part.. but before that you have to make sure you have no vacuum or boost leaks .. idle surge will happen if you are leaking vacuum from throttle body gaskets or intake manifold gasket ... it could also be TPC sensor messing up

 

[pecka]

Sorry I failed to mention the car has not been ran in a year. Do you think if I went and drove the hell out of it the problem might go away or is it not a good Idea to drive it at all.

 

[pecka]

how would I check for vacuum or boost leaks?

 

[blackGSX2g]

There is a website that shows how to build a boost leak testor...but I forgot which one, maybe someone can chime in and help.

For mine, basically I took a 3'' PVC pipe end with a screw on cap. Then, I drilled a hole in the cap and threaded it with a 1/4'' air compressor nipple. After that, I put glue on the threads of the PVC pipe and screwed them together. Then, I put a rubber coupling on the end of the PVC pipe and tightened it around the intake of the turbo.

Then hook the air compressor up to the nipple on the PVC and let 'er rip. Keep the pressure kinda low though, you don't wanna have hoses poppin off everywhere.

Watch your boost gauge to see if pressure dropps off quickly, or if you hear a hiss somewhere, then you have a boost leak. If you can't track it down just by sound, spray a bit of soapy water on your hoses to see if you can find the leak that way.

Good luck!

 

[pecka]

do you think it would hurt to drive the car?

 

[pecka]

drove the car today, every thing works great except the bouncing rpms and high idle as soon as you hit the gas it is fine. Where is the idle speed control motor located?

 

[Aikouka]

drove the car today, every thing works great except the bouncing rpms and high idle as soon as you hit the gas it is fine. Where is the idle speed control motor located?

It's right below the throttle body. I took mine out after a year of sitting around, and I found seeds in its port. It was weird.