SC High idle

[sabeo.m]

Hi everyone, i did a quick search and couldn't find the answer i was looking for...Hopefully someone can chime in.

I'm getting idle @ 3k rpm's after shutting down the engine (hot) and starting it back up again anywhere after 10-15 minutes. If i wait about a 1/2 hour to 45 minutes, the engine ides where it should. Any thought's? When this happens I have to slowly get into gear and then let out the clutch so that the RPM's drop, but the moment i plant the clutch pedal the RPM's increase again until I can begin normal driving. I was thinking it was the Idle Control Valve/frequency valve, the Auxiliary Air Regulator or EGR Return Valve-not sure which one...

My CIS is in pretty good shape, all new vacume hose's and air box/seal. air
valves and the above mentioned are original. I appreciate any help, TIA.

[autobonrun]

I recalled a thread on a related discussion (attached); different rpm's but a similar discription. You might also consider buying the K-Jetronic troubleshooting guide. It doesn't cover everything but is not a bad paperback to have in your P-car collection.

79 911SC idle increasing with engine temp



Amazon.com: Porsche Troubleshooting Guide K-Jetronic: Books

[jimrs2000]

Try pullimg the vacuum hose off of the decel valve and pluging the hose, I use a large self tapping screw.

[sabeo.m]

Thanks for all the replies, I have not had time to look into it yet, but will post my findings.

[KNIGHTRACE]

drop clutch in 1st