fast idle on cold start up
 

upon a cold start up, my 79SC will jump immediately to a 2500 rpm idle and stay there until warm up. I suspect that I have a faulty auxilary air valve problem. Is my assumption correct, or could this be a warm up regulator instead? input is greatly appreciated.

Check your electrical connection to the AAR. Should be 12 volts at the connector. You can also measure the resistance through the heater coil. Sounds like the AAR is working, but its internal heater isn't.

I doubt if it's a WUR problem. It can keep a car from idling high, but it won't cause a car to idle high.

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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

Isn't that what the idle is supposed to do upon a cold start up? How long does it stay at 2500 RPMS? I have problems because my cold start idle does NOT go above 1K RPMs.



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Paul
78SC Targa

while it's at high cold idle, tap the air reg with a small hammer and see if the idle drops. if so that's the problem.

thanks for the feedback. The high idle hangs on for about 3 minutes, then drops down to normal. In the height of winter, it will take about 10 minutes for the idle to drop. Hopefully it is not too harmfull for the engine to be running that hard while cold.

There is a method by which you can adjust this. Check the Search for this. Basically you are very carefully moving a pin so that the bimetallic spring affects the disk that permits more or less air (thus high idle setting).

Jw

What he has to determine is if the AAR is closing off because of engine heat, or if the internal heater coil is working.

The fact that it closes off at all shows that it is basically functioning.



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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY