MULTIPLE DRIVEABILITY CONCERNS FOR 2.5L ENGINE

MODELS AFFECTED: 1987-89 CENTURYS WITH 2.5L ENGINE (VIN CODE R) 1987-88 SKYLARKS WITH 2.5L ENGINE (VIN CODE U)

This bulletin cancels and supersedes Buick bulletin 88-6E-11. This bulletin contains new and revised calibrations to address additional driveability conditions.

Some 1987-89 Centurys and Skylarks may exhibit one or more of the following driveability conditions:

1. Hard hot engine restart. 2. Intermittent higher than "Normal" idle. 3. Spark knock (detonation). 4. Code 42.

If these conditions cannot be addressed through normal service procedures, they may be repaired by installing the appropriate hardware as outlined below.

SERVICE PROCEDURE

1. Use a scanner to determine the PROM I.D. that is currently in the vehicle.

2. Look for that PROM I.D. in Table 1 or Table 2 as indicated below, and select the corresponding required parts:

If the major condition is hard hot engine restart, use Table 1. If hard hot engine restart is not the major problem, but the condition is intermittent high idle (similar to cold fast idle), spark knock, and/or Code 42, use Table 2.

3. Install the new parts and verify that the driveability conditions have been corrected.

WARRANTY INFORMATION

To repair Intermittent Higher Than "Normal" Idle, Spark Knock, and/or Code 42:

Labor Operation Number: T1316 Labor Time: 0.4 Hr. Trouble Code: 92

To repair Hard Hot Engine Restart with or without any of the above driveability conditions:

Labor Operation Number: T1314

Labor Time for the following car lines: A N - - 1.6 Hr. 1.7 Hr.

Table 1

(*) VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW PROM NEW NEW PROM FUEL FUEL I.D. PROM PROM I.D. SENDER PUMP CAR N/Y TRANS (SCAN) PKG.P/N LABEL (SCAN) P/N P/N --- --------- ------ ------- ----- ------ --- --- A 87-88 AUTO 2702 16143580 ATBY 3551 25093744 25115764 A 87-88 AUTO 2782 16143580 ATBY 3551 25093744 25115764 A 87-88 AUTO 9522 16143580 ATBY 3551 25093744 25115764

N 87 AUTO 1272 16143457 ATBU 3521 25092769 25115925 N 87 AUTO 9532 16143457 ATBU 3521 25092769 25115925 N 87 MAN 1282 16143452 ATBR 3491 25092769 25115925 N 87 MAN 9542 16143452 ATBR 3491 25092769 25115925

(*) Note: In addition to the required parts above, each application in this table also requires the installation of a "rubber bumper" package (P/N 25004553) and a "pulsator" package (Part Number 25094266).

Table 2

* VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW NEW

MODEL PROM I.D. NEW PROM PROM PROM I.D. CARLINE YEAR TRANS PROM I.D. PKG. P/N LABEL (scanner) ------- ---- ----- --------- -------- ----- --------- A 87-88 AUTO 1222 16143580 ATBY 3551 A 87-88 AUTO 2702 16143462 ATCC 3591 A 87-88 AUTO 2782 16143462 ATCC 3591 A 87-88 AUTO 5402 16143580 ATBY 3551 A 87-88 AUTO 9522 16143462 ATCC 3591 A 88-89 AUTO 1532 16143545 ATBM 3461 A 88-89 AUTO 5132 16143545 ATBM 3461 A 88-89 AUTO 5932 16143545 ATBM 3461 (*)A 89 AUTO 0671 16143467 ATCD 3601 N 87 AUTO 1272 16143466 ATBP 3481 N 87 AUTO 9532 16143466 ATBP 3481 N 87 MAN 1282 16143463 ATBL 3451 N 87 MAN 9542 16143463 ATBL 3451 N 87-88 AUTO 1232 16143457 ATBU 3521 N 87-88 AUTO 6402 16143457 ATBU 3521 N 87-88 MAN 1242 16143452 ATBR 3491 N 87-88 MAN 6412 16143452 ATBR 3491

(*) Note: Only applicable to vehicles equipped with 215/60-R14 tires (RPO QMB).

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.