Weird idling problem

[Nabyar]

The car starts up and idles fine before and after it has warmed up. However, after about 5-10 of driving, the idle will raise up to about 1,500-2000 RPMs. There is no stuttering in the the RPM band or anything so it runs fine.

After it did this I parked it back into my garage and left it running. I made the idle right with a couple turns of the BISS screw and throttle body cable bracket and then proceeded to go back out and drive. Did it again.

Whats everyone thinking? Bad ISC?

 

[crankbender]

BISS backing out probably. Try changing the o-ring on the BISS (#5 i believe) and/or using some vibratite on the BISS. Alternately silicone will work in place of vibratite.

 

[rice_rocket]

What are your temps? If the car is too hot or too cold it will raise the idle to try to compensate for it. My car always starts to heat up in stop and go traffic, rpms can go up to 3K.. just found out my fan was dead when I replaced it for my SBR turbo.. I've experimented with the overheating issue.

 

[2much_bost4u]

I had similar problem on 92 AWD and I disconnected a single wire connector that is located above the idle motor and then I adjusted the bliss to lift the idle and that has got me by. It is not perfect but it is quite driveable. Better than buying a new idle control motor in my case.

 

[Nabyar]

Originally posted by rice_rocket
What are your temps? If the car is too hot or too cold it will raise the idle to try to compensate for it. My car always starts to heat up in stop and go traffic, rpms can go up to 3K.. just found out my fan was dead when I replaced it for my SBR turbo.. I've experimented with the overheating issue.

This is something that is concerning me. The temps didn't seem to go up above half way, but I did notice that one of the fans stoped working. I tried taking a fan from my old 90 talon and put it on. It doesn't make sense but what you're talking about it probably the problem. Any idea on what would make the fan stop working?

 

[DSMAddicted]

Hello Naybar.

Originally posted by Nabyar
but I did notice that one of the fans stoped working.

You know that one of the fans is the "AC" fan, right?
It's not supposed to be on at all times, although many DSMers like me wire them so that they both run together.

As far as your idling problem is concerned, although it seem to happen after 5-10 minutes of driving which would be enough for a full warm-up, try blocking off your FIAV.

For a complete thread full of advices on how to get rid of most Idling issues, check out my old post about ISC rebuilding.

Good luck, let us know how it goes.

Walter