DETONATION.TIP IN,SAGS AND/OR ENGINE STOPS AFTER CHOKE OPENS

Model and Year 1981 IMPALA/CAPRICES EQUIPPED WITH CALIFORNIA EMISSION SYSTEMS WITH 3.8L ENGINES

TO: ALL CHEVROLET DEALERS

Should a vehicle be received with this condition, all engine electronic and fuel control functions should be checked per the check list included in this bulletin to insure that all are within manufacturers' specifications.

After all engine systems are confirmed to be operating as designed, a new recalibrated EGR (17111295) and PROM (1226932) released for service should be installed. Both EGR and PROM must be installed to repair this condition. Do not install one without the other.

Check List

EGR Valve system operation,

Accelerator pump system operation - includes checking discharge, and check ball seating, and utilization of viton accelerator pump,

Vacuum hoses, fittings, and connections,

Ignition timing,

Carburetor float level,

CCC wiring proximity to high-voltage wiring,

EFE system operation,

Thermac air cleaner operation,

Exhaust back pressure,

Carburetor mixture control solenoid adjustment.

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.