For 1990-2009 cars

# STALL, HES.AFTER COLD START DIAGNOSIS AND PROM P/N'S

#### VEHICLES AFFECTED: 1986-87 'F' CARS WITH 2.8L (VIN CODE S) MPFI ENGINE AND 4 SPEED AUTOMATIC TRANSMISSION

Some 1986 and 1987 'F' cars with 2.8L MPFI engines and 4 speed automatic transmissions may experience one or more of the following conditions at 4 DEG C (40 DEG F) to 21 DEG C (70 DEG F) ambient temperatures:

Stall after cold start.

RPM sag or stall when shifting from neutral to drive immediately after cold start.

Cold driveaway hesitation.

To service this condition inspect for the following and repair as necessary.

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

2. Low minimum idle speed. (Specification is 550 plus or minus 50 RPM in drive, automatic transmission.)

3. Openings in the EGR transfer tube.

If the condition persists, check PROM I.D. with scan tool. If the PROM I. D. is not any of the following numbers, replace the PROM with one of the service PROMS listed in the following chart.

Scan tool reading of PROM I.D.: 8419, 8420, 9891, 9901, 9911, 9921 . SERVICE PROM APPLICATION

#### MODEL SALES AIR SERVICE CONDITIONING PROM #

86 Camaro Federal Yes 16080006 No 1228419 California Yes 16080011

86 Firebird Federal Yes 16080020 " No 1228420 California Yes 16080015

87 Camaro Federal Yes/No 16080006 California Yes/No 16080011

87 Firebird Federal Yes/No 16080020 California Yes/No 16080015

#### NOTICE: THE ABOVE PROMS ARE FOR OFO CARS WITH 2.BL PORT FUEL INJECTED ENGINES WITH 4 SPEED AUTOMATIC TRANSMISSIONS.

Use applicable labour time and labour operation numbers.

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.