I have a 1982 911 that has a demon that my local mechanic can’t seem to resolve. When it is started, while still cold, the RPM’s vacillate from 900 to 1600 until it warms up. This sometimes accompanied by a failure to start after the car has been warmed up. Further, when I attempt to start the vehicle I sometimes hear a “pop” in the motor coming from the motor. Invariably the car won’t start again until it is thoroughly cooled down. Does anyone have a solution to my problem? Who is the foremost Porsche mechanic near Michigan?
If your car has MFI, Porsche’s mechanical fuel injection, it can be very finicky and need either tuning or pump rebuilding. Porsche’s fuel injection systems, MFI or not, are spec tuned monsters and unless you are very mechanically inclined, it is best to find a vintage porsche shop to help tune it back up. Buy a good 911 repair manual and follow the procedures/read pelican parts forums to learn what needs to happen or start calling shops and asking about their experiences before you take it anywhere else, throwing money at a tuning problem only a knowledgeable Porsche tech knows.