Bad Idle Surge, But Sorta Goes Away w/ Idle Pos. Switch Disconnected

[scottr126]

Alright heres my problem. I just recently got my head rebuilt and a rebuilt trans put in my Galant VR-4. I did all the work myself but I am no newbie to DSM's. The problem Is now I have really really bad idle surge, ALL THE TIME. It never did it before I did all the work and disonnected the battery.

I took off the ISC and tested its ohms and they were all 29 ohms (good). And I really have no clue what it could be.

But one thing I noticed is if I disconnect the Idle Position Switch then the surging goes away but the Idle Sits at 2k no matter how I adjust it. Does this mean anything or does anyone have any ideas on what this means??

Thanks.

 

[steve]

But one thing I noticed is if I disconnect the Idle Position Switch then the surging goes away but the Idle Sits at 2k no matter how I adjust it. Does this mean anything or does anyone have any ideas on what this means??

It goes away because the ECU no longer thinks the car is idling and so stops cutting fuel because the idle speed is way out of limits. In otherwords disconnecting the IPS is a bandaid.

You should track down where the air leak is thats causing the high idle condition. Since the head of off that means all of the intake is suspect. Might be quickest to start off with a pressure test and the soapy water looking for bubbles.

Steve