SURGE AFTER TCC ENGAGEMENT NEW PROM P/N'S LISTED

1985-87 FIREBIRD MODELS EQUIPPED WITH 5.0L OR 5.7L PFI ENGINES (ENGINE CODES F AND 8)

On some 1986 Grand Prix and Bonneville models with the 5.OL (LG4) engine and 4 speed automatic transmission (MW9) may experience the following customer comments of:

1. Surge after TCC lock-up. 2. Detonation on light acceleration. 3. False Code 53 - EGR Control Error

If normal service procedures in the Shop Manual do not correct, a new service PROM with revised calibration is now available.

The model application are:

Year Model Engine Trans. Emissions PROM P/N --- ----- ------ ----- --------- -------- 1986 Grand Prix 5.OL 4 Spd. California 1228478 Bonneville Auto

1986 Grand Prix 5.OL 4 Spd. Federal 1228479 Bonneville Auto

Use applicable labor time and 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.