HESITATION/STALL AFTER COLD START-NEW PROM MAY REPAIR

VEHICLES AFFECTED: 1986 A-CAR W/2.8L (VIN W) AND AUTO. 3-SPD. TRANSMISSION

Some owners of 1986 A-cars with 2.8L multi port fuel injection (MPFI) engine and a 3-speed automatic transmission may experience a stall after cold start or an engine hesitation during a cold driveaway.

To service this condition, which generally occurs at approximate temperatures of 10 - 21 DEG Celcius 50 - 70 DEG Fahrenheit complete the diagnostic procedures per Section 6 of the Service Manual. Specific attention should be given to the following items and repair as required:

1. Loose or leaking air duct between mass airflow (MAF) sensor and throttle body.

2. Low base idle air rate.

3. Openings in the EGR transfer tube.

If the condition persists, replace the PROM with one of the following service PROMS, which may be obtained from CANSPO. (See the following chart).

IMPORTANT: The new service PROMS are for A-cars with a 2.8L port fuel injected engine and a 3-speed automatic transmission.

1986 - A-CARS W/ 2.8L PORT FUEL INJECTED ENGINE AND 3-SPEED TRANSMISSION

BODY TRANS. SCANNER SERVICE PROM STYLE AXLE RATIO A/C I.D. PART NUMBER ----- ---------- ---- ----- ----------- SEDAN F75 YES 7451 16137339 COUPE

SEDAN, F75 NO 7461 16137342 COUPE

SEDAN, F17 YES 7811 16137795 COUPE

SEDAN, F17 NO 7661 16137415 COUPE

WAGON F17 YES 7481 16137344

WAGON F17 NO 7491 16137345

WAGON, F75 YES 7521 16137348 STE

WAGON F75 NO 7531 16137349

POLICE PKG. 9C1 YES 7561 16137353

POLICE PKG. 9C1 NO 7571 16137354

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.