GM Service Manual Online
For 1990-2009 cars only

REVISED IDLE SPEED CONTROL ISC HAS SILENT THROTTLE SWITCH

A revised Idle Speed Control Assembly was introduced on Dualjet carburetors for the 3.8L V-6 engine (VIN Code 9) in December of 1982. Use has been extended to Quadrajet carburetors used on the 4.1L V-6 engine (VIN Code 4), and Dualjet carburetors used on the 3.0L V-6 enaine (VIN Code E), and 3.8L V-6 engine (VIN Code A). The new ISC assembly is identified by the numeral "II" on the motor housing, as shown.

The new feature is a silent throttle contact switch that does not "Click" when actuated. When checking operation of the throttle contact switch on ISC II, follow present Service Manual procedures.


Object Number: 86635  Size: MF

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.