INCREASED IDLE RPM/ENGINE START/STALL/SAG/HESITATION. Chevrolet Camaro 1994

SUBJECT: INTERMITTENT INCREASE IN ENGINE IDLE RPM; INITIAL ENGINE START/STALL AND/OR SAG/HESITATION ON DRIVE AWAY FOR AUTOMATIC TRANSMISSION EQUIPPED VEHICLES (NEW "FLASH" PROM)

MODELS: 1994 CHEVROLET CAMARO 1994 PONTIAC FIREBIRD WITH 3.4L ENGINE (VIN S - RPO L32)

CONDITION:

SOME OWNERS MAY EXPERIENCE TWO DIFFERENT CONDITIONS. THESE CONDITIONS CAN BE ADDRESSED WITH THE USE OF THE SAME NEW "FLASH" PROM.

1. AN INTERMITTENT INCREASE IN ENGINE IDLE RPM.

2. VEHICLES EQUIPPED WITH AN AUTOMATIC TRANSMISSION MAY EXPERIENCE "COLD START STALL," "HESITATIONS," AND/OR "SAG."

CAUSE:

THERE ARE TWO CAUSES, DEPENDING ON THE CONDITION BEING ADDRESSED.

1. A NON-ZERO TP SENSOR READING DURING A CLOSED THROTTLE CONDITION MAY CAUSE AN INTERMITTENT INCREASE IN ENGINE IDLE RPM.

2. VARIABILITY IN THE VOLATILITY OF COMMERCIALLY AVAILABLE FUELS MAY CAUSE THE AIR FUEL RATIO TO BE TOO LEAN UPON COLD ENGINE STARTS.

CORRECTION:

A NEW "FLASH" PROM IS AVAILABLE TO CORRECT BOTH CONDITIONS.

1. THIS NEW PROM HAS ENHANCED SOFTWARE TO ELIMINATE A NON-ZERO TP SENSOR READING DURING A CLOSED THROTTLE CONDITION.

2. A CALIBRATION CHANGE WAS MADE TO THE AUTOMATIC TRANSMISSION EQUIPPED CALIBRATION TO DIMINISH "COLD START STALLS," "HESITATIONS," AND/OR "SAGS."

NO OTHER DRIVEABILITY ISSUES ARE ADDRESSED WITH THIS "FLASH" PROM.

VEHICLES BUILT AFTER THE VEHICLE IDENTIFICATION NUMBERS BELOW WILL HAVE THIS CALIBRATION ALREADY INSTALLED BY THE VEHICLE ASSEMBLY PLANT.

MODEL VIN

CHEVROLET CAMARO 2G1FP22S0R2152803 PONTIAC FIREBIRD 2G2FS22S4R2221034

PARTS INFORMATION:

THE NEW "FLASH" PROM WILL BE AVAILABLE ON THE JANUARY 1994 CD RELEASED BY STG. FOLLOWING ARE THE PART NUMBERS:

PART NUMBER TRANSMISSION EMISSION TYPE ----------- ------------ ------------- 16203271 AUTOMATIC CALIFORNIA 16203281 AUTOMATIC FEDERAL 16203291 MANUAL NATIONWIDE

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: T0500 LABOR TIME: 0.3 HOUR

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS ONLY. BULLETINS ARE WRITTEN TO INFORM THOSE TECH- NICIANS OF A CONDITION POSSIBLY OCCURRING ON A VEHICLE, OR TO PROVIDE INFORMATION ASSISTING IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS, AND TRAINING TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THE BULLETIN APPLIES TO ALL VEHICLES. SEE AN AUTHORIZED GM DEALER FOR INFORMATION ON WHETHER A SPECIFIC VEHICLE MAY BENEFIT FROM THE INFORMATION.