POOR COLD DRIVEABILITY HESITATION,STALL,STUMBLE

1986 6000, FIERO, AND GRAND AM CARS WITH 2.5L L4 (VIN CODE R & U) ENGINE, MD9 3-SPEED AUTOMATIC TRANSMISSION, AND 2.39 (F62) , 2.84 (F-17) OR 3.18 (F-75) RATIO TRANSAXLE

Some customer comments on poor cold driveability may be received on 1986 6000, Fiero, and Grand Am models. The comments may range from hesitations, sags, and stumbles to cut-out, usually on first drive- away attempt after cold start.

These conditions may be caused by PROM calibrations that are too lean under some cold start driveaway conditions.

Should any vehicles with above described cold driveability condition be received and normal service procedures do not correct the condition, the following list of service PROMS are available from WDDGM.

Service PROM Model Engine Transmission Axle ------------ ----- ------ ------------ ---- 16062202 6000 2.5L 3-Speed Auto. 2.39 Ratio 16064305 6000 2.5L 3-Speed Auto. 2.84 Ratio 16060865 Grand Am 2.5L 3-Speed Auto. 2.84 Ratio 16062222 Fiero 2.5L 3-Speed Auto. 3.18 Ratio

Use Applicable labor operation number and labor time for PROM replacement.

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.