Engine Controls - Poor Driveability Corrections
Model Year 1983Bulletin No. 83-143
File in Group 64A
Number 17
Date July 83
SUBJECT: DRIVEABILITY CORRECTIONS - 4.1L ENGINE/LC4
MODELS AFFECTED: ALL FEDERAL 1982 & 1983 REGALS AND REGAL WAGONS EQUIPPED WITH A 3-SPEED TRANSMISSION, CODE MX2, LESABRES EQUIPPED WITH A 4-SPEED TRANSMISSION, CODE 200-4R MXO, AND ELECTRAS
A new 4.1L/LC4 calibration has been released for production and service on the above models. This new driveability fix is to be used for dealer correction of any one of or combination of the conditions listed below, when it has been determined that affected systems are within specifications and are functioning normally.
The changes consist of the following:
1. New thermac sensor
2. New PROM
The following conditions describe when to use the changes:
1. Poor cold acceleration maneuvers
2. Tip-in stumble or sag during warm-up and excessive burst knock
Before a decision is made to install the new parts, the vehicle should be road tested, if possible, for the owner described conditions and vehicle systems checked to determine if adjustments are within specifications. Unless all areas listed on the checklist are correct, a parts change will not be effective for the purpose intended.
One part cannot be installed without the other.
Zone authorization is required prior to usage of the parts.
PARTS ORDERING INFORMATION
^ Thermac Sensor 8997916
^ PROM Regal 1226481
LeSabre & Electra 1226482
WARRANTY INFORMATION
^ Thermac sensor and PROM
Labor Operation T0119
Labor Time 0.7 Hrs.
Trouble Code 92
System performance check will not be required with this change.
BURST KNOCK (MOMENTARY DETONATION) CHECKLIST
^ Ignition Timing
^ EGR Valve System Operation
^ Vacuum Hoses and/or Connection Leaks
^ Carburetor for Lean Operation
^ Deposits in Combustion Chambers
^ Intake Valve Seals not Sealing
^ MAP/BARO Sensor Operation
^ E.F.E. Operation
^ T.A.C. Operation
^ Overheating-Cooling Sys. Prob
^ Incorrect Spark Plug
^ Bad Fuel
^ E.S.C. not Working (If Equipped)
COLD DRIVEABILITY HESITATION, STUMBLE OR SAG CHECKLIST
^ Accelerator Pump System Operation (Pumpshot)
^ Vacuum Breaks
^ Choke
^ Carburetor Float Level
^ EGR Valve Operation
^ Park-Neutral Back Up Light Switch Adjustment
^ Thermac Air Cleaner (T.A.C.) Operation, Including Stove Pipe to Air Cleaner
^ HEI Operation
^ Evaporative Emission Control System (EECS)
- Purge Solenoid Operation
- Hoses and Hose Connections
- Canister Vent Valve Operation
^ Base Timing and Electronic Spark Timing (EST)
^ Early Fuel Evaporation (EFE) System
^ Mixture Control Solenoid Checks
- Dimensionally Setting of Carburetor per the Procedure in the 1983 Buick Chassis Service Manual using Tools J-33815-1 and J-33815-2
- Spark Plug and Plug Wires