HARD START ON HOT RESTART/ INCREASED IDLE SPEED. Chevrolet Corvette 1991

******************************************************************* SUBJECT: HARD STARTING DURING A HOT RESTART, INCREASE IN IDLE SPEEDS, AND IDLE FLUCTUATION (REPLACE MEM-CAL)

MODELS: 1990-91 CHEVROLET CORVETTE WITH 5.7L ENGINE (VIN J - RPO LT5) AND MANUAL 6-SPEED TRANSMISSION (ML9)

CONDITION:

SOME OWNERS OF 1990 CORVETTES MAY COMMENT ON IDLE FLUCTUATION, INCREASE IN IDLE SPEED AFTER A HOT RESTART, AND AN INCREASE IN ENGINE SPEED DURING A VEHICLE COAST TO STOP WITH CLUTCH DEPRESSED.

SOME OWNERS OF 1991 CORVETTES MAY COMMENT ON A HARD STARTING CONDITION DURING A HOT RESTART.

CORRECTION:

THE CALIBRATIONS HAVE BEEN REFINED TO ADDRESS THESE CONCERNS. REPLACE THE MEM-CAL WITH THE DESIRED UNIT FROM THE CHARTS BELOW.

PART INFORMATION:

MODEL BROADCAST SCANNER PART BODY YEAR CODE I.D. NUMBER STYLE AXLE ----- --------- ------- ------ ----- ---- 1990 AYBK 3921 16163905 COUPE 3.45

1991 BFXB 3431 16193416 COUPE 3.45

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

LABOR OPERATION: T0500 LABOR TIME: 0.5 HOUR

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.