idle too high and shearching

[spec guy]

what should I be looking to adjust to stabilize the searching idle?

[968rz]

Vacuum leaks.

[John_AZ]

+1^

If this if for your '83 944, I would check for a vacuum leak.

Change the vacuum lines and all hose clamps.

Do the "soap Bubble" test perfected by mytrplseven:

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/624343-vacuum-system-test-soooo-easy.html

You idle stabelizer is also a problem on the early cars.---Oil and grime gets into the unit but not easy to clean as the late type. Unit is expensive and may not solve the problem.

Rebuild the TB with a kit from Bruce Arnn at arnnworx.com

Throttle Body Reseal kits for Porsche

Unplug the O2 sensor and see if it stops searching.

Change the engine temp and coolant sensors.

Do a compression test and leak down test.

Remove the intake and change the AOS seals and all hoses under the intake.

Rebuild the injectors.

More? Sure, just a few to start with or eliminate the areas you have already done.. I am sure I missed a few.

GL
J_AZ

[Slam]

John, do you mean AAV and not idle stabilizer? A stuck Auxiliary Air Valve will cause hunting idle. A pain to get to with the intake on the car but it can be cleaned.

[uvachief]

I would also do a compression test. If you have worn or broken rings and oil is choking the engine, this will cause the idle to fluctuate and surge up and down. If you do the compression test and one or more of the cylinders are low, have fun rebuilding the top end.

[John_AZ]

Originally Posted by Slam

John, do you mean AAV and not idle stabilizer? A stuck Auxiliary Air Valve will cause hunting idle. A pain to get to with the intake on the car but it can be cleaned.

Slam you are correct--my part name error--part #9.



http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/737623-how-do-you-test-early-auxiliary-air-regulator.html

J_AZ

[pfarah]

I found a way to remove the Aux Air Regulator without taking off the intake. You have to remove a few other parts but after about three times, I've got it down pretty well. Take a look at the intake manifold from the front of the engine bay, remove the j-hose and associated vacuum hoses that connect to it. You can use an extension to remove the two bolts that secure the AAR; be careful of hose 13 and 15 (shown on the diagram above) because they will crack/break if original. I must tell you that replacing hose 15 can be a bear. Once all the hoses have been loosened, simply rotate the AAR 90 degrees and shimmy it toward you. If the valve is original, you may wish to replace rather than clean it. Cleaning the valve only works for a while (ask me how I know). Replacing the AAR transformed my 84 into a well-oiled machine, that is until the next series of problems arose. Anyway, PM me if you any specific questions and good luck!

Patrick