1G ISC 90-91 rewire question

[speedricer06]

Hey guys I tried to do my best to search a lot before I ask a question but I couldn't find an answer.

I believe my ISC motor is bad on my 1990 TSI. It dies when depressing clutch, makes crazy buzzing noises when trying to compensate my idle..yadda yadda. But my question is: Can I rewire a 1991 ISC that I have laying around to work on my 1990?

Does anyone know the wire diagrams for this? The plugs are different and I was wondering if anyone has done this before?

I'm a cheapie and have one laying around. Any info would be appreciated! Or maybe if someone has a 1990 ISC laying around let me know. Thanks!

 

[BOBS90TURBO]

I am almost sure it can be done, Have you tried turning up you BISS idle screw, this might help fix the dieing

 

[doggo]

Can i rewire a 1991 ISC that i have laying around to work on my 1990? Thanks!

See question #11, here: http://www.dsmisc.com/dsmweb-dw/faqs.html

 

[speedricer06]

Well I appreciate it, I put the other one on and made an extension for the wires.

But now I have a different problem, the idle is way high like 2000-3000rpms. I've played with the BISS screw and it only brings it down to around 2000. I checked to make sure the throttle cable is loose enough, throttle plate is closed.

I have no idea, please help!

 

[doggo]

With the BISS completely closed you should be able to just about cut off the engine. Did you seat the ISC correctly (not ####-eyed, no oring damage) so its not leaking air into the TB at the ISC/FIAV seal?

Are you playing with BISS/ RPM with your idle ground pin grounded? Make sure you are.

 

[NOSLO2PT0]

, the idle is way high like 2000-3000rpms...ive played with the biss screw and it only brings it down to around 2000, checked to make sure the throttle cable is loose enough, throttle plate is closed... I have no idea.. please help![/U]

Make sure your idle set screw isn't keeping the throttle plate open. That's the thing that's sticking up, and has a single male prong on the end of it. Will have a black connector at the end of the wire that attaches to it.

 

[speedricer06]

Ya I'll probably check the closed throttle screw tomorrow. I grounded both for the pins for setting the BISS and it didn't do much difference than when they weren't grounded.

I also tried unplugging the ISC and it didn't do anything, I put in another spare ISC that I had on a different spare TB and it didn't help either. I tried putting my finger over the BISS screw, couldn't feel any vacuum and it didn't affect the idle.

Maybe TB gasket when I took it off it broke the seal and the gasket is bad now since its old and hard? I'm also going to measure the size of hose and pipe I need for a intake pressure tester.

Any ideas where I can buy an individual valve stem from? Thanks for the help!

 

[speedricer06]

Well, I thought my ISC was bad because it was dying when I'd push in the clutch and now its got a really high idle.

Well I put in a couple different good ISC's and still cant figure out the problem.

It's idleing really high I replaced the BISS o-ring, the ISC o-ring, TB gasket, checked the throttle cable tension, the throttle closed switch, EGR gasket, still high idle.

The only thing is that the idle is fine when I ground the two terminals for setting the BISS, but when I unground it the idle goes really high like around 3k.

I'm getting very irritated and would really appreciate some help here. Thanks!

 

[speedricer06]

Well, its got something to do with my ISC, if i unplug it and start the car it runs fine and idle normal but when i blip the gas it almost dies then restabilizes...Maybe the 3 different ISC motors I have tried are junk??????????

 

[95AWD6Bolt]

I just had the same problem. I tried different isc's from junkyards and got the same result, high idle. Eventually i went Here to get a brand new isc at a good price, put it in and it idles great now. This will cost more than a junkyard isc but youll know that you definately have a good isc.

 

[freshlane]

have you messed with the throttle cable recently?

 

[speedricer06]

Ive already checked the tension in the throttle cable and its loose enough for the throttle plate to be fully closed..so yes i have messed with it lately