SERVICE MANUAL UPDATE SEC.6E3- C2 DRIVEABILITY & EMISSIONS

SUBJECT: SERVICE MANUAL UPDATE/SECTION 6E3-C2-DRIVEABILITY/EMISSIONS (REVISED FUEL CUT-OFF SPECIFICATIONS)

MODELS AFFECTED: 1990 - '91 REGAL WITH 3.1L ENGINE (VIN CODE T)

This bulletin revises the fuel cut-off specifications for the 1990-1991 Regals equipped with 3.1L (VIN T) engines.

To prevent possible engine damage from over-speed, the Electronic Control Module (ECM) "cuts-off" fuel from the injectors when engine speed is above approximately 6200 rpm with the vehicle in any forward gear or reverse, and approximately 4000 rpm in park or neutral. To prevent tire damage, the ECM also has a fuel cut-off in excess of 100 mph (161 km/h) based on speed rating of the tires.

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.