Idle Surge Problems

[shad0wsoda]

I know there are a bunch of threads covering idle surge but I've tried a bunch of different suggested fixes and nothing has worked. The car started surging right as it gets warm and switches off from cold idle. So already the IAC motor has been replaced with a brand new one, checked for vacuum leaks (and fixed the one found), the TB cleaned and the throttle cable adjusted. I'm stuck now and not sure where to turn next. O2 sensor, MAF? The car has dsm link and was last programmed by someone who apparently didnt know what they were doing so could that create a problem? Thanks in advance for any and all help!

 

[98MitzuGST]

the maf could definitely do it, because before its warmed up it doesn't look at the maf signal, you can unplug the maf when its idling and if the problem goes away its to blame if not then it could be a number of other things when i had mine go it was causing all kinds of issues until i canned it and went speed density

 

[jcastello214]

i know this sounds funny and im not sure if its the same for a 2G but on my 1G nonturbo I put the throttle body gasket on upside down and chased an idle surge for days.. I only found it with my finger feeling under the throttle body. . Apparently the gasket is thinner on one side then it is on the other but fits and doesnt cover the passages for the FIAV and ISC all the way.

 

[PlanZero]

Not trying to hijack, but my idle just started surging today. I noticed when I put her in neutral and rev it a few times it seems to die down. Its holding at around 1200, and I have to fight her by pushing on the brakes to get her to stop.

 

[98MitzuGST]

check for vacuum leaks and try cleaning throttle body and making sure the throttle cable is properly adjusted. these are the easiest things to start with and narrow it down

 

[Lou98GSX]

do you have a stock 2g throttle body or 1g

 

[patrick ellsworth]

Did you take off your TPS when cleaning your TB? It may be out of adjustment www.plymouthlaser.com/tps.htm
You can test it without removing the tps or throttle body.

 

[fabian95tsi]

I had just recently got my tsi running and tuned and I had a horrible idle due to the biss turned out all the way, i screwed it in all the way in and it went away. Since then backed it out just a bit ro adjust my idle.

 

[Slobonator4G63]

Id honestly check a few the above mentioned. It could be due to a bad idle switch. make sure your tb Is not sticking. my personal suggestion make the home make tester and throw 20 30 lbs threw intake and listen, if you hear air soapy water in a spray bottle and go to town.