|
I had the same problem with my 1979 911SC.
I found that the fix was a careful adjustment of the Idle air mixture (the small hole between the Throttle body and the fuel distributor that takes the 3 mm Allen) and the idle screw (a large screw with a spring that has a slot for a screw driver but can be adjusted by hand) on the left side of the throttle body.
If you turn the 3mm Allen clockwise you en-richen the idle mixture, and if you turn the idle adjustment screw counter clockwise you increase the idle speed. To check if the idle mixture was too rich I pulled a plug to see the electrode tip, black too rich, gray/white just right.
enrich the idle mixture a little, like no more than a 1/8 a turn of the 3mm allen, then see if you can use the idle adjustment screw to bring it down to 950 RPM. Blip the throttle in-between adjustments.
Good luck
|