IDLE SPEED UNSTABLE SURGE ON DESCENDING GRADES

MODELS AFFECTED: SOME 1987 SKYHAWKS EQUIPPED WITH 2.OL OHV-TBI ENGINES (VIN CODE 1)

There may be customer comments on some early production Skyhawks, concerning the following conditions:

1. Surge on long descending grades with a slightly cracked throttle, and more pronounced at higher altitudes with either a manual or automatic transmission.

2. Unstable idle speed on higher mileage manual transmission vehicles only, where the idle RPM will oscillate up to 300 RPM over a continuous period with steady operating conditions.

The following is a listing of Service PROMS and their applications:

"J" Body Automatic Transmission Service PROM #16071643

"J" Body Manual 4-Speed Transmission Service PROM #16071647

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.