speed control
 

I have been fixing stuff on my 85 911. Next thing to tackle is the speed control. I notice that I can increase the speed with the little lever, it holds for a moment then drops off. So if it speeds up then part of it must work right? I see the speed unit on the back of the engine compartment on left side. Everything looks good and hooked up. One of the large hoses back there seems to have a cut in it. Don't know for sure if it part of speed control. What do you think? Nick

Can't help you directly but if your problem ends up being electrical, see here especially post #3. Search also under keywords "Tempomat" or "speed-control".

http://forums.pelicanparts.com/porsche-911-technical-forum/394659-understanding-vdo-cruise-control-amp.html

Hey Nick,

A picture will help allot.

If you see a tear in a hose, replace it. If it is the vacuum for the cruise control, it will need that to set the proper speed desired.

J

Nick,

The large hose could be a breather hose, is the cut all the way through? Like Draco said, a picture would help. Regarding your C.C. it sounds like you have a vacuum leak. Do you have a Bentley's Repair Manual? You need to identify the hoses that are part of the cruise control system, then be sure the hoses are fresh and tight.

I have a pretty good working C.C., but it can be set a 70 MPH and over a 30 minute period it will slowly drop off 2-3 MPH so it will need to be bumped up to maintained the desired speed. It's still a nice feature on an old car for an old shoe...