LOW POWER/LACK OF PERFORMANCE INSTALL TRANS. TORQUE CONV.

SUBJECT: LOW POWER/LACK OF PERFORMANCE (INSTALL TORQUE CONVERTER,TBI, MEMCAL)

MODELS: 1991-92 C/K AND R/V TRUCKS WITH 5.7L ENGINE (OVER 8500# GVW)

Some owners of 1991-92 C/K and RN trucks with the H.D. 5.7L engine (VIN K) and 4L80E (RPO MT1) transmission may comment of low power and/or lack of performance under normal operating Conditions/ temperatures. These low-power comments are mostly on heavy throttle maneuvers such as towing, highway passing, and on uphill grades.

The transmission torque converter, engine and transmission calibration (MEMCAL) were not optimum in matching the engine torque curve.

VEHICLES INVOLVED

This service fix is for all 1991 and 1992 models built before the following VIN breakpoints:

Pontiac East: GMC=E523373 Oshawa: GMC=1525884

SERVICE PROCEDURE

1. Install transmission torque converter P/N 08685994.

2. Install Memcal per chart below:

New New Broadcast Memcal New Code I.D. Memcal Memcal Scan Type Axle Prom Kit Label Tool ---- ---- -------- --------- ------ C, R All 16173069 BAAX 3001 (2-Wheel Drive)

K, V All 16173073 BAAY 3001 (4-Wheel Drive)

3. Install TBI Body Kit P/N 17112900.

SERVICE PARTS INFORMATION

Parts are currently available from GMSPO.

WARRANTY INFORMATION

Labor Operation: Mem-Cal: T-0500 Labor Time: 0.2 Hr. Labor Operation: Torque Converter and TBI: T-7516

Labor Times: "C" Models: 2.9 Hrs.

"K" Models: 4.5 Hrs.

"R" Models: 2.5 Hrs.

"V" Models: 3.5 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.