Cold Idle Speed Stalling

[AirmanPika]

OK so I've been working this issue for the better part of a year now. Not been spending too much time on it tho due to other priorities. I'm wondering how often the idle speed motor goes out and if it would be a good idea to swap it out. The main issue is that the car will start fine and idle fine when parked, but once I drive out of my complex to the first intersection the car will try to die unless I apply gas (which is hard when trying to also apply brake and clutch). Right now the only thing I can think of is that the Bosch Idle Speed Motor may need replaced. Also, when I was yanking the motor out the pipe of agony (joy) came with it rather easily. As far as I recall the O ring is gone along with the retaining cup. Could a leaky seal where it enters the intake also cause cold idle issues? Once the car warms up it is golden.

I've already worked out any issues with mixture, the microswitch, and the throttle so tis is my next area to look at.

[AirmanPika]

OK one correction, the brass ring and O ring are in place. I looked back at my photos and realized I did replace the O ring (the brass ring stayed in place). It does appear there may have been some leakage though due to the pipe not quite being in 100% possibly based on the corrosion on the pipe. Its very tiny but that's all it takes sometimes.

I am also curious if there are any other cars that used this model (or compatible) Bosch idle speed motor. At the very least I could pull one from a junkyard engine for testing purposes.

[nkemp]

Before you replace the idle speed motor, try cleaning it. Plug one end and spray some cleaner in the motor. Let it sit and repeat. In addition to cleaner I also used PB Blaster which is a penetrating oil. Since I had an extra pigtail to connect to the motor I used it to bang the idle motor to each extreme a couple times (center pin +12Vdc and the two outer pins are ground). My theory, and it is only a theory, is that the motor normally only needs to operate in a narrow range of operation. Thus it can get gummed up (corroded?) outside that range. Forcing it to the full extremes helps break up the gunk outside of normal range. Remember, I'm subject to being wrong without notice :)

Any of the Bosch 500 series motors is compatible with our setup. A Volvo 260 is one source. You can read more at: http://dmctalk.org/showthread.php?7492-Swapped-Yellow-amp-White-Bulkhead-connectors-Damage

Even if you do salvage a new motor, you should clean it before using since it may be worse than the one you are replacing.

Also, using something to test for vacuum leaks (propane, carb cleaner , etc), verify that you don't have any air leaks. In the above mentioned topic you'll read that the cleaner I used did not cause the engine to increases speed so make sure that your test material does.

Also, my recomendation is to not adjust anything (throttle, microswitch, curb idle, etc) unless:
- someone has already messed with it
- all other issues are resolved

Verify = yes. Adjust = not yet. The reason is that there is very few reasons that these items should go out of adjustment via normal usage. There is likely something else causing the problem if the car is still set to factory.

[David T]

Before you replace the idle speed motor, try cleaning it. Plug one end and spray some cleaner in the motor. Let it sit and repeat. In addition to cleaner I also used PB Blaster which is a penetrating oil. Since I had an extra pigtail to connect to the motor I used it to bang the idle motor to each extreme a couple times (center pin +12Vdc and the two outer pins are ground). My theory, and it is only a theory, is that the motor normally only needs to operate in a narrow range of operation. Thus it can get gummed up (corroded?) outside that range. Forcing it to the full extremes helps break up the gunk outside of normal range. Remember, I'm subject to being wrong without notice :)

Any of the Bosch 500 series motors is compatible with our setup. A Volvo 260 is one source. You can read more at: http://dmctalk.org/showthread.php?7492-Swapped-Yellow-amp-White-Bulkhead-connectors-Damage

Even if you do salvage a new motor, you should clean it before using since it may be worse than the one you are replacing.

Also, using something to test for vacuum leaks (propane, carb cleaner , etc), verify that you don't have any air leaks. In the above mentioned topic you'll read that the cleaner I used did not cause the engine to increases speed so make sure that your test material does.

Also, my recomendation is to not adjust anything (throttle, microswitch, curb idle, etc) unless:
- someone has already messed with it
- all other issues are resolved

Verify = yes. Adjust = not yet. The reason is that there is very few reasons that these items should go out of adjustment via normal usage. There is likely something else causing the problem if the car is still set to factory.

Vacuum leaks will reduce the effectiveness (control) of the idle motor. As a temporary stop-gap "trick", you can bump up the idle speed a little so the car is more drivable. Make sure the idle switch is being closed and is making continuity when the linkage is at idle. That is what turns on the idle motor circuit. Good advice to check everything before trying to "adjust" the problem away.
David Teitelbaum

[AirmanPika]

Looks like problem solved finally. While I did clean out the motor I think the bigger issue was that the pipe of agony wasn't quite in all the way allowing a small leak at the top. The way my hoses were installed caused it to be pulled out slightly when the motor was bolted down. Readjusted and now it stays put. Car doesn't stall either :)

[nkemp]

I had a problem with the hose connecting the motor to the pipe. It was old and deteriorating and thus leaked air. When I sprayed cleaner on it the RPMs decreased (as opposed to increasing like normally expecting if it leaked) which caused me to take a closer look.