S-10 TRUCK STALL-PERFORM DIAG. REPLACE INOP. PARTS/NEW MEMCAL

SUBJECT: S-TRUCK STALL ON DECELERATION (PERFORM DIAGNOSTICS/MAKE ADJUSTMENTS, REPLACE INOPERATIVE PARTS-THEN REPLACE MEMCAL)

MODELS: 1991 S-TRUCKS WITH 2.8L ENGINES AND MANUAL TRANSMISSIONS

Some 1991 S-trucks with 2.8L engine and manual transmission may experience engine stall when the clutch is pushed in during deceleration.

This condition is caused by low fuel volatility and/or system component variability.

SERVICE PROCEDURE:

If any of the subject conditions are found, complete the following procedure:

1. Perform diagnostics as provided in the Fuel and Emissions section at the back of the 1991 S/T Service Manual. Make any adjustments that are required, or replace any inoperative parts.

2. If no other conditions are found using normal diagnostics, and this condition or conditions still exist, then replace the PROM with one from the following table.

PARTS INFORMATION:

Part Scan Number Description Code ID --------- ------------- ---- ---- 16170408 PROM (3.42 and AZNU 0551 3.73 Axle)

16170409 PROM (4.11 Axle) AZNW 0561

Parts are available at GMSPO.

WARRANTY INFORMATION:

Labor Operation Number: T0500 Labor Time: 0.8 Hours

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.