warmup problem, help please....

[911SC520]

Ok I have a 1980 SC and i know that the AAV (when cold) allows are to bypass the throttle body resulting in high idle. Also, when working properly it is suppose to shut when engine is warm. Here is my issue, my car is fully warm but the idle is still at 2k rpms. I know that the AAV functions properly because when it is warm to touch the car idles fine.

Last night i was driving the car and the idle would not go down. I opened up the deck lid and touched the AAV, and to my surprise it was still cold. Temperature outside was maybe 50 degrees. The car is stored inside of a garage and after about 20 min of driving, the AAV was still cold even though the engine was warmed up. Any ideas why this would be? I don't think the AAV is malfunctioning i think this is an issue of outside air keeping the AAV cold. Any thoughts would be greatly appreciated.

In the summer time it warms up just fine. But keep in mind I live in AZ so it is usually 110 degrees outside.

thanks in advance,

Mark

[doug_porsche]

Mark,

Good news. These are actually really simple devices. You have two wires going to the AAV. One goes to ground, one to 12v. Inside the AAV is a an electric heater and a temperature sensitive wound spring.

Unplug the AAV wires and start the car. With a volt meter you should see 12v on one of the wires. If so you can shut the car off and check the other wire (brown??) and it should be your ground wire. If both of those check out, the problem is with your AAV its self.

Doug

[boyt911sc]

Mark,

You are referring to the auxiliary air regulator (AAR) as AAV. You got the parts mixed up and I suggest that you pick-up some reference manual to familiarize yourself. There are Bosch references that uses AAV for AAR.

For reference and discussion in this forum, AAR is the CIS component responsible for the by-passed air needed for cold start. This is located between runners #5 & #6. Bentley manual is a highly recommended reading material. Inspect and check your AAR (AAV to you) that it closes when the engine is warm. Do an oven test and measure the heating resistance of the coil. Keep us posted.

Tony

[Paulporsche]

Mystery Train did a great writeup on AAR testing and rebuilding. There are many other threads on AArR issues. The AAV only comes into play during startup.