Pulsating Engine Idle???
 

My 79 911 SC has a certain pulsating (Slight rise and fall in RPM) at idle. Seems to run fine once at operating tempature.. It has a 3.0 with modifided cams, pistons, exhaust, etc., etc.

Any thoughts?

Thanks,

Alex in NJ

Was the CIS retained after all the mods? If so how old is the system?

The issue is most likely fuel metering. CIS is not compatable with most cam or piston upgrades. Old or worn metering plates may be out of tolerance for adjustment as well. Carbs also have issues when cold due to a temporary lean condition.

Gout is what people get on a rich diet. A fluctuating idle is what engines get on the same diet.

Joe

Get the mixture adjusted and go from there. Chances are there's nothing wrong.

Doug
75 911S