Engine Surge At Part Throttle or While Climbing Grade

BULLETIN NUMBER:
92-6E-136

SECTION:
6E

NUMBER:
2

CORPORATE
REFERENCE NUMBER:
236513

DATE:
October 1992



SUBJECT:
ENGINE SURGE AT PART THROTTLE OR WHILE CLIMBING GRADE (REPLACE MEMCAL AND EGR VALVE)

MODELS:
1991-92 S-TRUCK WITH 2.5L ENGINE



CONDITION:
Some owners of 1991-92 S-trucks with the 2.5L L38 engine (Vin Code A), Federal emissions, manual transmission and 3.73 rear axle may comment of an engine surge occurring in the RPM range of 2000-2500 RPM, at a steady throttle or while climbing a slight grade.

CAUSE:
Unstable combustion due to EGR (Exhaust Gas Recirculation) flow.



CORRECTION:
Install a new memcal and EGR valve.

Memcal P/N: 16183223

Scanner ID: 3241

Broadcast Code: BCNX

EGR Valve P/N: 17112238

SERVICE PARTS INFORMATION:
Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Labor Operation: T0500 Memcal

Labor Time: .5 Hr.

Labor Operation: J6270 EGR Valve

Labor Time: .6 Hr