C 2500 Truck 2WD V8-350 5.7L (1988)
PROM - Programmable Read Only Memory: Customer Interest
A/T - Low Power/Lack of Performance With 4L80E
GMC NUMBER:
92-6-100
GROUP:
6 Engine Diagnosis
DATE:
June 1992
CORPORATE
NUMBER:
236507R
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 R/V 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.
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:
