C 2500 Truck 2WD V8-454 7.4L (1988)
PROM - Programmable Read Only Memory: Customer Interest
Engine - Surges
GMC NUMBER:
88-T-157
GROUP:
6E-Engine Emission
DATE:
August, 1988
CORPORATE
NUMBER:
836512R
SUBJECT:
ENGINE SURGE
MODELS:
1987-88C/K, R/V TRUCK WITH 7.4L (VIN CODE N) ENGINE
THIS BULLETIN CANCELS AND REPLACES BULLETIN 88-T-95, ALL COPIES OF WHICH SHOULD BE DESTROYED. THIS REVISION IS
TO UPDATE PROM P/N FOR MANUAL TRANSMISSION AND ADD AN AUTOMATIC TRANSMISSION PROM.
Some 1987-88 C/K and R/V trucks with 7.4L engines may experience customer comments of engine surge. If the condition described cannot be repaired
using normal service procedures, a revised calibration PROM should be installed (see chart). Parts are currently available from GMSPO.
After the PROM change, if surge is still present at highway speeds, refer to Bulletin 88-T-141 dated July, 1988, for MAP sensor repositioning.
Use Labor Operation:
T7655
Labor Time:
.6 Hr.