BLACK SMOKE AFTER INJECTION PUMP REPLACEMENT

SUBJECT: BLACK SMOKE ONLY AFTER INJECTION PUMP REPLACEMENT (CHECK GASKET POSITION/INSTALL NEW GASKET)

MODELS: 1994-95 CHEVROLET AND GMC TRUCK C/K MODELS WITH 6.5L TURBO DIESEL ENGINE (VIN S - RPO L56)

CONDITION:

SOME OWNERS MAY EXPERIENCE EXCESSIVE BLACK SMOKE DURING ACCELERATION IMMEDIATELY AFTER ENGINE OR FUEL SYSTEM REPAIR OF THEIR VEHICLE. THE PREVIOUS REPAIRS MUST HAVE INCLUDED REMOVAL OF THE INTAKE EXTENSION, SUCH AS INJECTION PUMP REPLACEMENT. IF THE INTAKE MANIFOLD EXTENSION HAS NEVER BEEN REMOVED AND THERE IS A COMMENT OF BLACK SMOKE, REFER TO THE SYMPTOM SECTION OF THE DRIVEABILITY, EMISSION, AND ELECTRICAL DIAGNOSIS MANUAL.

CAUSE:

WHEN REASSEMBLING THE INTAKE EXTENSION TO THE INTAKE MANIFOLD, THE EGR TOWER GASKET (3) (P/N 10191428) WAS EITHER NOT INSTALLED OR WAS NOT LOCATED IN ITS PROPER POSITION ON TOP OF THE INTAKE MANIFOLD EGR TOWER. THE PURPOSE OF THE GASKET IS TO SEAL NONREGULATED EXHAUST GASSES FROM THE INTAKE SYSTEM.

CORRECTION:

REMOVE THE INTAKE EXTENSION, CHECK TO SEE IF THE GASKET (3) (P/N 10191428) IS IN THE PROPER POSITION ON TOP OF THE INTAKE MANIFOLD EGR TOWER. IF THE GASKET IS NOT IN THE PROPER POSITION OR IS DAMAGED, INSTALL A NEW GASKET. THE GASKET IS ROUND AND THE METAL SIDE FACES UP WHEN INSTALLED PROPERLY.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

FIGURES: 1 ATTACHMENTS: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER." THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS OCCURRING 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 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.

COPYRIGHT 1994. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.