DRIVEABILITY IMPROVEMENT UPDATE CERTAIN EMISSON DEVICES

Subject: 1982 J2000 DRIVEABILITY (ALL EXCEPT CALIFORNIA)

To improve driveability characteristics, a production running change has been incorporated on 1982 J2000 vehicles approximately July 20,1981.

The changes involve new electronic fuel control calibration and revisions to the EGR, TVS, Air Management Valves, and Carb Base Idle Speeds.

These production changes are intended to improve such driveability characteristics as tip-in hesitation, level road surge, weak driveaway after cold start and under certain conditions, engine stalling (with clutch disengaged during coastdown).

Some early J2000 cars may exhibit one or more of these conditions and may be corrected by performing the service identified in the following chart.

When using the chart, determine the automatic transaxle model by referring to the stamped metal tag located adjacent to the shifter shaft on the transaxle.

It is essential that the correct vehicle equipment combination be determined and that all the service actions identified in the chart be performed to assure that the vehicle remains in a certified configuration.

NOTE: It is essential that only the specified part numbers be used. PROM calibrations vary for each engine- transmission combination and should not be interchanged. The PROM Code is printed on the PROM body.

VEHICLES EQUIPMENT CONDITION ACTION REQUIRED

TRANSMISSION ECM A/C (REPLACE OR *ADJUST)

3.18 AUTO. 16018071 N LEVEL ROAD SURGE EGR VALVE P/N 17068212 CI 16011711 B 16018131 B

3.18 AUTO TIP-IN HESITATION *CARBURETOR P/N 17081701 CI AND/OR LOW ADJUST BASE IDLE WITH ISC SPEED PERFORMANCE RETRACTED TO 725 RPM 16018071 N EGR P/N 17068212 PROM P/N 1225387 (3392AMJ) 16011711 B EGR P/N 17068212 PROM P/N 1225387 (3392AMJ) 16018131 B EGR P/N 17068212 PROM P/N 1225388 (3397AMK)

2.84 AUTO 16018061 Y TIP-IN HESITATION AIR,MANAGEMENT VALVE CJ AND/OR LOW P/N 17082700 SPEED PERFORMANCE PROM P/N 1225374 (3214ALZ) 16018121 N AIR MANAGEMENT VALVE P/N 17082700 PROM P/N 1225375 (3222AMA) 16018241 Y AIR MANAGEMENT VALVE P/N 17082700 PROM P/N 1225378 (3238AMD)

16018171 N AIR MANAGEMENT VALVE P/N 17082700 PROM P/N 1225379 (3276AMT) 16018381 N *CARBURETOR P/N 17081700 ADJUST BASE IDLE WITH ISC RETRACTED TO 725 RPM AIR MANAGEMENT VALVE P/N 17082700 PROM P/N 1225375 (3222AMA)

MANUAL 16018161 Y SEVERE IDLE EGR TVS P/N 373510 EXCEPT CAL. DEGRADATION IN PROM P/N 1225376 (3227AMB) 16018211 Y COASTDOWN ENGINE EGR TVS P/N 373510 RPM 1100-1800 PROM P/N 1225380 (3374AMF)

MANUAL 16018161 Y WEAK DRIVE AWAY EGR TVS P/N 373510 EXCEPT CAL. AFTER COLD START PROM P/N 1225376 (3227AMB) 16018201 N EGR TVS P/N 373510 PROM P/N 1225377 (3233AMC) 16018211 Y EGR TVS P/N 373510 PROM P/N 1225380 (3374AMF) 16018251 N EGR TVS P/N 373510 PROM P/N 1225385 3375AMU) 16011701 N EGR TVS P/N 373510 PROM P/N 1225386 (3386AMH)

A/C: Y YES N = NO B = BOTH A/C AND NON-A/C

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.