COLD START STALL/SAG/ COLD ROUGH IDLE. Buick Century 1995

REVISION: 08/18/95

THIS BULLETIN IS BEING REVISED TO ADD THE 1995 MODEL YEAR, REFLECT NEW A/C L0W PRESSURE VALUES FOR TURNING ON THE A/C COMPRESSOR CLUTCH, NEW PROM AND PCV ELBOW PART NUMBERS. PLEASE DISCARD BULLETIN 47-65-23 (SECTION 6E - ENGINE FUEL & EMISSIONS). ----------------------------------------------------------------------

SUBJECT: COLD START STALL/SAG/HESITATION/COLD ROUGH IDLE OR IMPROPER DEFROSTER OPERATION AT MODERATE TEMPERATURES (INSTALL NEW PROM)

MODELS: 1994-95 BUICK CENTURY 1994-95 OLDSMOBILE CUTLASS CIERA WITH 3100 V6 ENGINE (VIN M - RPO L82)

CONDITION:

SOME OWNERS MAY EXPERIENCE A COLD START STALL, COLD TIP IN HESITATION AND/OR A COLD ROUGH IDLE AFTER EXTENDED IDLING. ADDITIONALLY, IN 40-50 F AMBIENT TEMPERATURES SOME OWNERS MAY COMMENT OF FOGGING ON THE INSIDE OF THE FRONT WINDSHIELD WHICH DOES NOT CLEAR WITH THE DEFROSTER ON.

CORRECTION:

THE FOLLOWING GUIDELINES SHOULD BE FOLLOWED IF NORMAL DIAGNOSTICS FAIL TO DETERMINE THE CAUSE OF THE DRIVEABILITY CONCERN.

STEP 1

INSPECT THE PCV VACUUM CONNECTOR TEE AT THE UPPER INTAKE PLENUM HOLE. IF LOOSE, REMOVE CONNECTOR AND INSTALL NEW CONNECTOR, P/N 12537524. A NYLON INSERT HAS BEEN ADDED TO THE CONNECTOR TO MAINTAIN THE OUTSIDE DIAMETER. ON THE PCV FRESH AIR SIDE, A NEW ELBOW FOR THE ROCKER COVER TO PIPE CONNECTOR HAS BEEN RELEASED, P/N 12537523.

STEP 2

INSPECT THE THROTTLE CABLE SYSTEM FOR PROPER ADJUSTMENT. CABLES THAT HAVE EXCESSIVE SLACK CAN CAUSE A DELAYED THROTTLE RESPONSE WHICH CAN BE PERCEIVED AS A HESITATION. SECTION 6C OF THE SERVICE MANUAL COVERS THE ADJUSTMENT OF THE ACCELERATOR CABLE.

STEP 3

AFTER INSPECTING THE PCV CONNECTOR AND THROTTLE CABLE FOR PROPER OPERATION, INSTALL A NEW PROM, P/N 16226503.

THE FOLLOWING GUIDELINES SHOULD BE FOLLOWED FOR COMMENTS OF FOGGING ON THE INSIDE OF THE WINDSHIELD.

STEP 1

INSPECT THE OPERATION OF THE A/C COMPRESSOR CLUTCH.

STEP 2

IF OPERATING AS INTENDED, REPLACE THE PROM WITH P/N 16226503. THE VALUES FOR THE A/C COMPRESSOR CLUTCH CONTROL HAVE BEEN CHANGED FROM DISABLING THE CLUTCH BASED ON THE A/C PRESSURE TRANSDUCER PRESSURE OF 38 PSI (NEW VALUE 33 PSI) OR LESS. IT WILL REMAIN DISABLED UNTIL THE A/C PRESSURE TRANSDUCER SENSES A RISE IN PRESSURE TO 47 PSI (NEW VALUE 37 PSI) OR GREATER.

PARTS INFORMATION:

PART BROADCAST QTY NUMBER NAME CODE SCANNER ID EMISSIONS

1 12537524 CONNECTOR -- -- -- VACUUM TEE

1 12537523 ELBOW, -- -- -- CONNECTOR

1 16226503 PROM BRFJ 6474 NATIONWIDE

PARTS ARE EXPECTED TO BE AVAILABLE ON SEPTEMBER 4, 1995 FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: J6980 VACUUM HOSE, REPAIR OR REPLACE LABOR HOURS: USE PUBLISHED LABOR OPERATION TIME.

LABOR OPERATION NUMBER: J6364 REPLACE PROM LABOR HOURS: USE PUBLISHED LABOR OPERATION TIME.

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