S10/T10 Blazer 2WD V6-262 4.3L VIN Z (1994)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
Engine - Backfire Upon Acceleration
File in Section: 6E - Engine Fuel & Emission
Bulletin No.: 47-65-22
Date: January, 1995
Subject:
Backfire on Acceleration (Correct Calibration)
Models:
1994 Chevrolet and GMC Truck S/T Models with 4.3L Engine (VIN Z - RPO LB4) and Manual Transmission (RPO MY2)
Condition
Some owners may experience a backfire condition upon acceleration.
Cause
Insufficient ignition timing advance in the spark calibration under some driving conditions.
Correction
More robust calibrations have been released to address this concern. THIS CALIBRATION WILL NOT CORRECT ANY OTHER DRIVEABILITY
CONCERN.
Important:
These service calibrations should ONLY be used if a backfire concern still exists in a vehicle WHICH HAS HAD THE BASE TIMING CHECKED
AND SET TO SPECIFICATION.
LAUNCH DETONATION MAY OCCUR IN VEHICLES SERVICED WITH THESE CALIBRATIONS;
particularly in vehicles which are heavily loaded or towing trailers.
Parts Information
Service "FLASH" calibrations are available starting with the December, 1994 CD ROM.
Warranty Information
