HESITATION/STALL AFTER COLD START-NEW PROM MAY REPAIR

Model and Year:1986 A-CAR W/2.8L (VIN W) AND 3-SPEED AUTOMATIC TRANSMISSION

TO: ALL CHEVROLET DEALERS

Some owners of 1986 A-cars with 2.8L multiport 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 50 - 70 degrees 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 GMSPO. (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.

Labor Operation Number: T1417 Labor Time: .5 Hours

CHART

A-CAR WITH 2.8L P.F.I. ENGINE AND 3-SPEED AUTOMATIC TRANSMISSION ---------------------------------------------------------------- AXLE NEW EMISSION VEHICLE AXLE OPTION SCANNER NEW SERVICE SYSTEM MODEL RATIO CODE A/C I.D. PROM P/N REMARKS ------ ----- ----- ---- ---- ---- -------- ------- CALIFORNIA A19,27 2.84 F17 YES 7431 16137337 CALIFORNIA A19,27 2.84 F17 NO 7441 16137338 FEDERAL A19,27 3.18 F75 YES 7451 16137339 FEDERAL A19,27 3.18 F75 NO 7461 16137342 CALIFORNIA A19,27 3.18 F75 YES 7471 16137343 CALIFORNIA A19,27 3.18 F75 NO 7581 16137367 FEDERAL A35 2.84 F17 YES 7481 16137344 FEDERAL A35 2.84 F17 NO 7491 16137345 CALIFORNIA A35 2.84 F17 YES 7501 16137346 CALIFORNIA A35 2.84 F17 NO 7511 16137347 FEDERAL A35 3.18 F75 YES 7521 16137348 FEDERAL A35 3.18 F75 NO 7531 16137349 CALIFORNIA A35 3.18 F75 YES 7541 16137350 CALIFORNIA A35 3.18 F75 NO 7451 16137352 FEDERAL A ALL - - 9C1 YES 7561 16137353 POLICE - - PACKAGE FEDERAL A ALL 9C1 NO 7571 16137354 POLICE PACKAGE FEDERAL A19, 27 2.84 F17 YES 7811 16137795 FEDERAL A19, 27 2.84 F17 NO 7661 16137415

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.