ENGINE MISSFIRE-HARD THROTTLE 2.0 TURBO/ REVISED PLUG GAP

VEHICLES AFFECTED: 1987 VEHICLES WITH 2.0L TURBO OPT. LT3 (VIN CODE M) ENGINE

Some engines may misfire under hard throttle, for example during turbo boost conditions. The miss is caused by excessively high ignition system demand voltage of the high gap (.060") spark plug and combustion conditions.

The misfire is repairable by installing a .035" gap spark plug with service P/N 5613820 (R42XLS, a previous 1986 turbo spark plug).

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.