911 2

i checked the idle air control valve using an ohm meter as described in the bentley mannual idle switch is fine checked as stated in the bentley mannual may be it is the motronic ecu i presume there is no way of testing this but to swap it with one that is tunning fine

Lorenfb

Here's ( www.systemsc.com/tshoot.htm ) an overview of the troubleshooting
steps.

KC911

You might want to try cleaning your ICV also. Following a suggestion on Pelican, after it checked out OK with a multimeter, I removed it and I could tell the 'plunger' or whatever is inside wasn't moving freely. I cleaned it out with Isopropyl alcohol a couple of times (shaking it back and forth), reinstalled it, and the idle was much improved. Hope this helps...

Keith

944ZEN

I have a ICV from a 91' for my new "project".
It would only move in steps, or as mentioned above the "plunger" was'nt moving freely.

I had to dismatle the ICV totally, and clean out old hardned oil deposit from cranck ventilation, and re-lubricate the bearings inside it. The Plunger is now moving freely so that it's position is only determined by the spring inside and the current applied to it.

Lorenfb

Here's another simple way to check the total functioning of the idle system:

1. Disconnect and remove the idle valve.
2. Fully close the valve using a small screwdriver.
3. Replace the valve without connecting the electrical connector.
4. Start the engine. The idle should be very low.
5. Connect the electrical connector. The idle should increase.
6. Stop the engine and disconnect and remove the idle valve.
7. Fully open the valve using a small screwdriver.
8. Replace the valve without connecting the electrical connector.
9. Start the engine. The idle should be very high.
10. Connect the electrical connector. The idle should decrease.

If the above checks O.K. the idle system via the Motronic unit & valve
are working properly.

911 Rod

Call me crazy, but I have this problem if I fill the oil level past 3/4.
Oil goes down, problem goes away.
Anyone else seen this?