uscarrera

Took spark plugs out, drivers side plugs 3-1 look lean passenger side 6-4 look darker with more carbon may be rich but not by much. Car idles rough, pulses when cruising but pulls strong when full on gas up to redline, any ideas where to look for solution. Have pity on a weber carb early 911 guy
Rich

BReyes

Have you found any debris in any of the jets, check valves or pumps? Ran through the balance sync mixture idle adjustment process?

Regards,

rusnak

yup, you need the carb sync tool and check the float level after cleaning out the jets. I envy the simplicity of this task.

uscarrera

Sorry did not make myself clear, I am having problems on my CIS 1980SC not my carb race car.
Thanks

theiceman

hmm this has a strange ring to it . A few years ago Bob ( a local lister and carrera owner ) broke the rings all on one side of the engine. The theory at the time was that whole bank of cylinders was running leaner than the other side but I am not sure we figured out exactly why.
With your SC it has a fuel distributor that dumps ( theoretically ) an equal amount of fuel to all cylinders , has a common coil and ignition. this is one for Pete and Steve for sure. you would have to start with fuel pressures I would imagine and work from there.

rusnak

If you have or can borrow an LM-1 fuel air gauge, and an inductive timing light, you can go a long way toward figuring it out. Also, have you checked the system fuel and control pressure?

Auto_Werks 3.6

Rich, Sounds like similar symptoms I had when I had some vacuum leaks. All my injector sleeves and seals were shot. Resealing the injectors and replacing the intake runner seals went a long way towards cleaning up the hunting at idle and cruise.