'83 turbo, very high idle after sitting out in the cold

r. a. wiessing · Post by **r. a. wiessing** » 24 Feb 2004, 22:37

sometimes ...after a cold night out my engine will start and rev to 2000+. it may stop in a mile or not for 20 miles. there doesn't seem to be any mechanical problem w/ the linkage as once underway the throttle responds normally, aside from not wanting to drop to a normal idle.

Volvord · Post by **Volvord** » 25 Feb 2004, 09:28

Check for a vacuum leak. Many of the rubber vacuum hoses will harden and crack with age.

A.Baker · Post by **A.Baker** » 27 Feb 2004, 00:50

Im haveing the same problem w/ one exception mine is random. I found that if I unplug the idle speed control motor thr problem is solved. This is only a temp. fix @ best. Removing the motor and cleaning it is also a good idea. As it may be gummed up from intake slober. If you find that you need one let me know I have a spare. If the part#s are the same we can talk $. Please let me know when you get it fixed Im desprate for help.

ozzimark · Post by **ozzimark** » 28 Feb 2004, 16:45

i tried unplugging my idle control motor, and the motor stayed at a steady 2000 rpm, but if i block off the tubing that goes to the idle motor, the car runs at 200-300rpm... not really sure what to think. does anyone know exactly how the idle control motor functions?

A.Baker · Post by **A.Baker** » 28 Feb 2004, 17:43

The motor is controled by the ecu. during cold starts, w/the a/c on and during hot starts. The ecu will open and close the motor as is needed.
The problem is you, I, dont have a way to test what one is causing it to stay open. We can get a repair manual from volvo BUT there are about 10 diffrent books and some cost 35$. When I get the proper one I will send you the info. In the mean time if you leave the key on and engine off. You should be able to feel the motor spinning. If it doesnt the motor or control has failed. Good luck.
A. Baker

Volvord · Post by **Volvord** » 28 Feb 2004, 22:07

The idle control motor is a stepper motor which controls an air bleed. The motor essentually opens and closes an air bypass by varying an opening between a cone and tapered seat.

The motor will not run continuously, it will quickly rotate one way or the other then stop. This cycle will continue to maintain the correct idle speed When you unplug the motor it will remain in the last posistion. If the motor or air valve is dirty it will be slow to react and can stick.

Try cleaning the motor by removing it and using a spray carburetor or intake cleaner to "spray" away any deposits. This may be enough to fix your problem

ozzimark · Post by **ozzimark** » 29 Feb 2004, 19:38

so it's a valve, not a pump? i guess this would make sense because the engine already has suction, so there is no need to pump anything into it, but rather open a valve to allow air to flow in