Ridiculously High Idling...Whats the prob?!

[90ttsiawd]

I have a 90 tsi and this problem first started out with idle surge around 1500-1800rpm but now the car pretty much idles at 2500 or sometims even 3000rpm constantly.....what could be causing this?

 

[gstowner]

Do a boost leak test first then report back with the results

 

[blcknspo0ln]

It also has to do with your TB allowing too much air to pass by. Try www.vfaq.com for more information about "idle surge". My bet is that your ISC is stuck open, allowing way too much air pass the TB and leading to your high idle. Other various things could be a backed out BISS or misadjusted TPS.

 

[prayforGSX]

i am having the same problem now. car had bad idle surgedid a boost leak test , found the intake manifold gasket leaking and the tb shaft seals were leaking. replaced intake manifold gasket. took tb all apart replaced seals, cleaned tb, isc looks to be good resistance between coils all around 30 ohms. put tb back on with new gaskets and car still idles way high around 2500 to 3000 rpms. i also made sure that the tps was adjusted right. i am pulling my hair out trying to figure this one out.

 

[90ttsiawd]

What does a boost leak test consist of?

 

[gstowner]

Build a tester like is shown in the pictures of the link. Remove your intake and Put the the tester on the inlet of your turbo. Then use an air compressor and shoot like 20 psi. in and listen for leaks. If you think you hear it leaking from a area spray some soapy water on and it will bubble if its leaking from there. Its a pretty simple process. If you have any questions just holler.


http://www.dsmtuners.com/forums/showthread.php?t=162466&highlight=boost+leak+tester

 

[90ttsiawd]

Alright will do.....thanks guys..

 

[femmeDSM]

It also has to do with your TB allowing too much air to pass by. Try www.vfaq.com for more information about "idle surge". My bet is that your ISC is stuck open, allowing way too much air pass the TB and leading to your high idle. Other various things could be a backed out BISS or misadjusted TPS.

I'll have to agree here.

Here's the direct link to this article.
http://www.dsm.org/how-tos/tttt/tttt3.html