STEADY STATE SURGE 45-55 MPH (NEW CALIBRATION). Buick Coachbuilder 1994

SUBJECT: STEADY STATE SURGE 45 TO 55 MPH (NEW CALIBRATION)

MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE AND IMPALA SS EQUIPPED WITH 5.7L ENGINE (VIN P - RPO LT1)

CONDITION:

VEHICLES BUILT FROM START OF PRODUCTION THROUGH MAY 10, 1994 (SEE VIN BREAKPOINTS LISTED BELOW) MAY EXHIBIT AN ENGINE SURGE CONDITION BETWEEN 45 AND 55 MPH WHEN AMBIENT TEMPERATURES ARE AT 30 DEGREES FAHRENHEIT OR COLDER UNDER THE FOLLOWING CONDITION:

1. THE ENGINE IS COOL BUT IN CLOSED-LOOP OPERATION. THE CONDITION DISAPPEARS WHEN THE ENGINE IS FULLY WARMED UP.

DIVISION SERIES VIN BREAKPOINTS (LAST 6 DIGITS) -------- ------ ------------------------------- BUICK B SOP THROUGH -429471 CADILLAC D SOP THROUGH -724427 CHEVROLET B SOP THROUGH -176334

CAUSE:

THE CALIBRATION WAS NOT OPTIMIZED FOR THIS SPECIFIC ENGINE OPERATING CONDITION.

CORRECTION:

NEW CALIBRATIONS HAVE BEEN RELEASED TO IMPROVE THIS CONDITION.

PART INFORMATION:

NEW CALIBRATIONS ARE AVAILABLE AND LISTED ON THE APRIL 1994 CD ROM (V032.061) FOR THE FOLLOWING VEHICLES:

VEHICLE TYPE (RPO) RATIO FUEL CALIB. P/N CODE ------------------ ----- ---- ---------- ---- CADILLAC 7000 LBS TRAILERING 3.42 UNLEADED 16207131 BLPD (GU6)

PUBLIC SERVICE STATION WAGON 2.56 UNLEADED 16207141 BLPF (GM8)

POLICE (9C1) 3.08 UNLEADED 16207151 BLPH (GU4)

POLICE (VZ2) 3.08 UNLEADED 16207161 BLPJ (GU4)

CADILLAC CONVERSION HEARSE 2.93 UNLEADED 16207171 BLPK ( 7200 LBS GVW (B9Q) AND COACH (GW9) BUILDER ( 7200 LBS GVW (V4U)

ALL EXCEPT PUBLIC SERVICE (1A2) 2.56 UNLEADED 16207191 BLPM (GM8)

ALL W/O TRAILERING PROVISION 2.93 UNLEADED 16207201 BLPN (V92) (GW9)

ALL WITH TRAILERING PROVISION 2.93 UNLEADED 16207211 BLPP (V92) (GW9)

CHEVROLET IMPALA SS (WX3) 3.08 UNLEADED 16207221 BLPR (GU4)

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY: LABOR OPERATION: J6355

USE PUBLISHED LABOR TIME.

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 THE 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.