HOT WEATHER DRIVEABILITY (INSTALL NEW FUEL SENDER/PUMP)

Subject: HOT WEATHER DRIVEABILITY (INSTALL NEW FUEL SENDER AND PUMP ASSEMBLY)

Models Affected: 1991-92 FIREBIRD MODELS WITH 5.0L TBI ENGINE (RPO L03)

CONDITION:

Some 1991-92 Firebird models with 5.OL TBI engine (RPO L03) may exhibit a hesitation/stall during an aggressive stop that may result in a pro- longed/hard restart. This condition has only been experienced during high ambient temperatures when the fuel gage reads one half full or less.

CAUSE:

The TBI fuel pump is ingesting air/fuel vapors when fuel is sloshed away from the fuel pump pick-up strainer.

CORRECTION:

Follow appropriate Service Manual procedures when diagnosing fuel re- related problems. When the above symptoms are present, verify the condition by checking the fuel system pressure for pressure loss during an aggressive stop above 35 mph.

If diagnosis indicates fuel pressure loss, a possible cause is the fuel pump losing prime. Vehicles may be repaired by replacing existing Fuel Sender and Pump Assembly with new assembly, P/N 25029778, with derated rollervane pump following applicable Service Manual procedures, Section 6C, Engine Fuel.

PART AVAILABILITY:

Parts are expected to be available on 04/19/93.

WARRANTY INFORMATION:

Labor Operation: L1200 Labor Time: 2.6 Hrs.

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.