Engine - Chuggle/Tip In Hesitation
No.: Reissue 82-T-124Section: VIt
Date: July, 1983
Subject: CALIFORNIA DRIVEABILITY - ALL 1982 CALIFORNIA IMPALA AND CAPRICE MODELS EQUIPPED WITH A 3.8L (LD5) ENGINE CODE A
TO: ALL CHEVROLET DEALERS
This bulletin replaces bulletin 82-T-124 dated November, 1982 due to a incorrect published EGR part number. Bulletin 82-T-124 should be destroyed and replaced with this reissue.
PROM, P/N 1225707, and EGR valve, P/N 17079787, with revised calibrations, are available for any combination of the conditions listed below which might occur on 1982 California Impala and Caprice models with 3.8L V6 engines. It must first be determined that affected vehicle systems are within specifications and functioning normally before installing these parts.
A. Chuggle at 40-45 mph
B. Tip-in hesitation
Vehicle should be road tested to verify the owner described conditions. Unless all other areas are correct, the PROM and EGR valve will not be effective. Use the attached check lists for additional assistance, as necessary.
A. Condition: Chuggle - also referred to as surge, is most noticeable at 40-45 mph, and should not be confused with "freeway hop", a common condition in many areas. Converter clutch engage speed is increased to 50 mph from 41 mph.
B. Condition: Tip-in Hesitation - may be experienced during either hot or cold operation, while going through a light or moderate acceleration period, from a stationary vehicle position.
If any one or combination of conditions exist, install both parts, PROM and EGR valve. These parts were used in production for 1982 model vehicles.
PARTS INFORMATION
Obtain the following two (2) parts from your GM Parts Division Warehouse:
Original Equipment # PROM ID
Prom, P/N 1225707 16030034 BOH
EGR valve, P/N 17079787
CHUGGLE CHECK LIST
^ Park-neutral back up light switch adjustment
^ Base ignition timing and total advance
^ Spark plugs and plug wires
^ HEI operation at problem speeds
- includes checking for correct distributor wave washer
^ Speedometer needle for fluctuation (sticking or kinked cable and/or speedo head will cause vehicle speed sensor (VSS) to engage - disengage TCC)
^ Evaporative Emission Control System (EECS)
- purge solenoid operation
- hoses and correct hose connections
- canister vent valve operation
HESITATION CHECK LIST
^ EGR valve system operation
^ Accelerator pump system operation - pump shot
^ Vacuum hoses, fittings and connections
^ Ignition timing
^ Carburetor float level 9/32 +/- 1/32
^ C-3 wiring proximity to high voltage wiring
^ EFE system operation
^ T.A.C. system operation
^ Overheating - cooling system problem
^ Incorrect spark plugs
^ Bad fuel
^ EGR override relay circuit
^ MAP/BARO sensor operation
WARRANTY INFORMATION
Labor Operation Number: T0112
Labor Time : 0.6 hours
^ Replace PROM and EGR valve system performance check not necessary.