CRANK/NO START RUNS ROUGH. Buick Regal 1994

REVISION: 12/01/94

THIS BULLETIN IS BEING REVISED TO CHANGE THE WARRANTY INFORMATION.

SUBJECT: CRANK NO START/RUNS ROUGH AFTER EXTREME COLD WEATHER SOAK (NEW FLASH CALIBRATION)

MODELS: 1994 BUICK REGAL AND SKYLARK 1994 CHEVROLET BERETTA AND CORSICA 1995 CHEVROLET LUMINA AND MONTE CARLO 1993-94 OLDSMOBILE CUTLASS SUPREME 1994 OLDSMOBILE ACHIEVA 1994 PONTIAC GRAND AM AND GRAND PRIX WITH 3100 ENGINE (VIN M - RPO L82)

CONDITION:

DURING EXTREMELY COLD WEATHER (-10 DEGREES FAHRENHEIT; -23 DEGREES CELSIUS AND BELOW), SOME VEHICLES MAY CRANK BUT NOT START OR DISPLAY A ROUGH IDLE CONDITION AFTER AN EXTENDED SOAK PERIOD.

CAUSE:

EXTENDED HIGH SPEED DRIVING FOLLOWED BY LONG EXPOSURE TO VERY COLD AMBIENT TEMPERATURES CAN RESULT IN ICE FORMATION OVER THE TIP OF THE FUEL INJECTOR. THE ICE IS FORMED WHEN MOISTURE FROM THE EXHAUST GAS INTRODUCED BY THE EGR SYSTEM DURING HIGH SPEED DRIVING CONDENSES IN THE INTAKE MANIFOLD AND FREEZES ON THE INJECTOR TIP DURING AN EXTENDED SOAK PERIOD IN VERY COLD AMBIENT TEMPERATURES. THIS ICE WILL RESTRICT THE FUEL FLOW THROUGH THE INJECTOR CAUSING ROUGH IDLE AND, IN THE WORST CASE, A NO START CONDITION.

CORRECTION:

A NEW ENGINE CALIBRATION HAS BEEN RELEASED TO ADDRESS INJECTOR ICING. THE NEW CALIBRATION WILL DISABLE EGR OPERATION IF COOLANT TEMPERATURE IS LESS THAN OR EQUAL TO 32 DEGREES FAHRENHEIT (0 DEGREES CELSIUS) AT START UP. EGR WILL NOT BE ENABLED UNTIL COOLANT TEMPERATURE REACHES 221 DEGREES FAHRENHEIT (105 DEGREES CELSIUS).

PART INFORMATION:

ALL NEW CALIBRATION NUMBERS WILL BE AVAILABLE FOR TECHLINE TOOLS STARTING WITH THE NOVEMBER CD RELEASE FROM STG.

IMPORTANT: DO NOT ATTEMPT TO ORDER THE CALIBRATION NUMBERS FROM GMSPO. THE CALIBRATIONS ARE PROGRAMMED INTO THE VEHICLE'S POWERTRAIN CONTROL MODULE VIA A TECHLINE TOOL DEVICE.

MODEL CALIBRATION YEAR CARLINE TRANS EMISSIONS NUMBER ----- ------- ----- --------- ----------- 1993 W - OLDSMOBILE A-4 NATIONWIDE 16209574 1994 L A-4 NATIONWIDE 16208594 1994 N A-4 NATIONWIDE 16208584 1994 W A-4 NATIONWIDE 16208574 1995 W - CHEVROLET A-4 NATIONWIDE 16208574 1995 W - CHEVROLET A-4 NATIONWIDE 16208624 POLICE 1995 W - CHEVROLET A-3 NATIONWIDE 16208614

WARRANTY INFORMATION:

LABOR OPERATION: T0500 LABOR TIME: .3 HRS.

FIGURES: 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 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.