What Would Cause This To Happen?

[Eric Mckenna]

I will start the car up and it will, as it should run up to 2k. BUT!!!
it will stay there until i let it warm up and then turn the car off and let it sit for a bout 2 minutes and then re-start the car then it goes to idle where it should..
is it the WUR?
gone bad?

any idea's it's an 83 SC

Eric

[AirCooledExcellence]

Hi Eric,

Have you checked the electrical connections to your AAV (Aux Air Valve)? It's on the right hand side of the engine.

Cheers

[Tim Walsh]

I don't know about the newer cars but that sounds like your cars still warm and has no need to idle at 2K after its warm. 2 minutes doesn't give alot of time for 3 gallons of oil to cool down.

just my speculation

[IROC]

I'm not going to suggest this is your problem, but I had a similar occurence on my 2.7 where it would run fine for a bit, then the idle would go up to 2k and I could not get it to drop back down. Then it would magically clear up. I figured it was some CIS problem. Nope. My throttle linkage was catching on a vacuum line (or possibly the fuel return line) right down there where it attaches to the engine and not allowing it to drop back to idle.

Doh.

Mike

[Gunter]

The engine needs more time to warm up then 2 minutes. AAV does not have an electrical connection; the AAR has. The voltage to the Aux. Air Reg. heats up the element inside and thereby closes the valve. I suspect that the heat from the engine has an effect on the AAR as well.

[AirCooledExcellence]

Sorry Eric, I meant AAR!

Cheers

[old_skul]

I've seen Eric's car in action; it never comes off of the warmup period high idle. Even fully warmed up it idles waaay high until he shuts it down, waits a bit, and restarts it.

[Eric Mckenna]

Thanks for the replies.. i'll check out some of the listed things and see what happensd.. if anyone else has some idea's on the matter please feel free to chime in.
Thanks!
Eric

[jason2guy]

2k is too high. try putting in a new AAR, bet that will solve your problem

[fred cook]

Eric,

When I first got my '80 911SC, it did EXACTLY the same thing you are describing. I kept looking for the problem and finally discovered that the electrical connector on the AAR was not pushed completely into the socket. Just to make sure that the AAR was actually working, I took it off (not too hard, requires an allen wrench and patience), put it in a freezer for about 5 minutes to cause it to open fully and let it sit on the workbench to warm up and close. Once I was convinced that it was working correctly and was warm (closed), I tried to blow air thru the AAR to check the seal on the rotary valve. After passing all tests with flying colors, I reinstalled the AAR and made sure that the electrical connection was correctly installed. It has worked perfectly ever since. Total cost of repair, about 1 hour labor and 0$.

Good Luck!

Fred Cook

[diy83sc]

Hey Eric,

Before you take the AAR off, try this. Take a small piece of wood or a soft hammer and gently tap the AAR the next time your idle hangs. If the idle drops, take Fred's advice. I had the same problem. Basically, the engine was not warming up as quick due to the constant flow of cool air at 2K rpm. Once the engine stops, the radiant heat is enough to get the AAR to close. Mine was gunked and is now okay after a light cleaning. I read this tip on another thread.

Tony

[Eric Mckenna]

Thanks guys..

Thanks very much! VERY HELPFUL!

Eric McKenna