Follow this procedure to adjust the idle speed in your 911 Carrera. If your idle speed is a bit higher than normal, it may need to be adjusted down, if it “hunts” on start-up or is higher than 900 rpm at normal running temperature. This can also happen on an 1987 Carreras if the original chip is #1267355236.
To reduce the base idle speed if necessary to 880 rpm, adjust the idle speed screw on the throttle body by two or three turns clockwise. The screw may be covered with a yellow plastic cap, which will need to be removed.
For a more exact adjustment, use a wire to bridge B and C in the rubber test socket on the left side of the engine compartment, located behind the black removable cover, and adjust the idle speed to 880 rpm at normal running temperature.
Properly adjusted, there should be no difference in idle speed with the jumper or without. Remove jumper when finished.