HESITATION OR STALL ON COLD ACCEL. (NEW CALIBRATION

SUBJECT: HESITATION OR STALL ON COLD ACCELERATION (NEW CALIBRATION WITH VIN BREAKS)

VEHICLES AFFECTED: 1990-91 J AND L CARS W/2.2L (LM3) AND 3T40

Condition:

---------- Some owners of 1990 and 1991 i and L cars with 2.2L (Vin IGI) engines may comment of an engine hesitation or stall during a cold acceleration.

Cause:

------ Low volatility fuel that does not fully vapourize in a cold intake manifold.

Correction:

------------- New PROM packages have been released which compensate for low volatility fuel during cold acceleration. Install the correct PROM package based on the chart below, and recommend that the owner use low octane fuel (87 or equivalent).

Vehicles Affected --------------------- Body Model Emissions Assembly Vehicles Style Year Type Plant Affected ----- ------ --------- -------- --------- J 1990 Federal (NA5) Janesville All Lordstown All

1991 Federal (NA5) Janesville All Lordstown VIN Prior to M7173516

L 1990 Federal (NA5) Linden All Wilmington All

1991 Federal (NA5) Linden VIN Prior to ME142136 Wilmington VIN Prior to MY159347

PROM Application

Body Emissions Broadcast Scanner PROM Part Style Type Code I.D. Number ------ ---------- --------- ------- --------- J Federal (NA5) AWWM 8321 16158344

L Federal (NA5) AWWP 8341 16158354

Parts are currently available from CANSPO.

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.