ROUGH IDLE - LOW DWELL LEAKING CARB BASE GASKET

IF A VEHICLE IS IN FOR A CUSTOMER COMMENT OF ROUGH IDLE AND THE TECHNICIAN FINDS A FIXED DWELL BELOW 10 DEGREES, THE CONDITION COULD BE CAUSED BY A CARBURETOR BASE GASKET. WITH A DWELL METER CONNECTED, ENGINE RUNNING IN CLOSED LOOP, CAREFULLY SPRAY CARBURETOR CLEANER AROUND THE BASE GASKET. DO NOT ALLOW SPRAY TO TOUCH ANY OTHER SURFACE. IF DWELL METER MOVES TOWARD A LEANER COMMAND (TOWARDS 50 DEGREES), THE CARBURETOR BASE GASKET IS MOST LIKELY LEAKING. BEFORE REMOVING, CHECK CARBURETOR RETENSION BOLTS FOR PROPER TORQUE AS A LOOSE CARBURETOR TO GASKET SURFACE COULD ALSO CAUSE THIS CONDITION.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.