More issues.... idling and shifting

[Yellowb1rd]

Sorry for being active on the forum today with so many questions. I have two issues which may be related.

My 78 911SC (stock) idles at 1800 RPM whether hot or cold. Starts right up (idles at about 1400RPM), even when cold, but soon afterwards, it begins to climb to 1800 RPM, even before it's at normal operating temperature. It's driving me crazy for obvious reasons, and is making it un-driveable in traffic, because I cannot shift into any gear when stopped at a light. I have to either shift into second while rolling to a stop (1st is impossible), or I have to actually shut the car off, put it into 1st, and then start the car. This has rendered the vehicle undriveable for me. I believe that the high idle may have something to do with the shifting issues, because of worn syncros, although I'll be crawling under the car to adjust the clutch cable at the shift shaft. Any pointers would be very helpful.

[ossiblue]

You haven't mentioned what you've checked out so far, so I'll assume nothing has been looked at.

Your idle is way too high, of course. Have you checked to see if the throttle cable/cruise control (if present) is stuck? Have you tried adjusting the idle with the adjustment screw on the left side of the throttle body? Most likely though, the screw will have no effect because I suspect an air leak somewhere that is allowing unmetered air into the system. This leak could be from one of the rubber hoses which connect the CIS components or one of the components itself--like the aux. air regulator being stuck open.

My suggestion is to first thoroughly check out all air/vacuum connections for integrity. There are several connections on the front side of the engine (the side toward the front of the car) that can only be seen with a mirror and flash light, so be prepared. Do a search on the forum for "air leaks" for more specific information.

I also suspect the transmission problem is connected with the fast idle. Nothing you described about the shifting issue is inconsistent with trying to shift a 915 into gear at high idle. Let us know what you find out.