LOW POWER/LACK OF THROTTLE RESPONSE (INST. DRIVE MOTOR). GMC Truck GMC MD Bus Chassis (B Model) 1991

REVISION: 06/23/94

THIS BULLETIN IS BEING REVISED TO ADD C/K MODELS, A NEW CONDITION AND TO REMOVE THE 7.4L ENGINE. PLEASE DISCARD BULLETIN 376519 (GROUP REFERENCE 6E - ENGINE FUEL AND EMISSIONS). ----------------------------------------------------------------------

SUBJECT: LOW POWER OR LACK OF THROTTLE RESPONSE/HOT RESTART DRIVEAWAY SAG (INSTALL NEW GOVERNOR/MEMCAL)

MODELS: 1989-94 CHEVROLET AND GMC B6, B7, D7, C6H, C7H, G3, P3, P4 AND C/K TRUCK WITH 4.3L V6 (VIN Z-RPO LB4), 5.7L V8 (VIN K-RPO L05), 6.0L V8 (VIN P-RPO LS0), OR 7.0L V8 (VIN M-LR0) ENGINES

CONDITION:

SOME OWNERS MAY COMMENT ON:

1. LACK OF THROTTLE RESPONSE ON TRUCKS EQUIPPED WITH GOVERNORS.

2. HOT RESTART DRIVEAWAY SAG, BOTH GOVERNOR AND NON-GOVERNOR TRUCKS.

CAUSE:

GOVERNOR/ENGINE CALIBRATION WAS NOT OPTIMALLY CALIBRATED FOR ALL OPERATING CONDITIONS.

CORRECTION:

IF NORMAL DIAGNOSTICS AND SERVICE PROCEDURES DO NOT CORRECT ANY OF THE ABOVE CONDITIONS, A REVISED GOVERNOR OR MEMCAL SHOULD BE INSTALLED.

PARTS INFORMATION:

APPLICATION DESCRIPTION PART NUMBER ----------- ----------- ----------- 1989-94 MEDIUM DUTY TRUCKS GOVERNOR 17113159 (B6, B7, D7, C6H, C7H)

1991-94 LIGHT DUTY TRUCKS GOVERNOR 17113159 (> 8600 GVW) W/GOVERNOR MEMCAL SEE CHART BELOW

1991-94 LIGHT DUTY TRUCKS MEMCAL SEE CHART BELOW (> 8600 GVW) W/O GOVERNOR

*** INSERT CHART HERE ***

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

LABOR OPERATION: J6364 - MEMCAL REPLACEMENT USE PUBLISHED LABOR OPERATION TIME.

LABOR OPERATION: J5410 - GOVERNOR REPLACEMENT USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 1

Object Number: 74757 Size: FS

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.