MULTIPLE DRIVEABILITY CONCERNS FOR 2.5L ENGINE. Buick Century 1988

VEHICLES AFFECTED: 1987-89 A/N/P CARS

This bulletin contains new and revised calibrations to address additional driveability conditions.

Some 1987-89 A/N-cars and 1987-88 P cars 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:

Use applicable Labour Operation Number.

Labour time: 0.4 hr.

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

Use applicable Labour Operation Number.

Labour Time for the following car lines: A N P - - - 1.6 Hr. 1.7 Hr. 1.4 Hr.

CHEVROLET ONLY.

Chevrolet Table 1 -- Table 1

(*) VEHICLE CONFIGURATION REQUIRED PARTS

CUR. NEW NEW CAR M/Y TRANS PROM PROM NEW PROM FUEL FUEL --- --- ----- I.D. PKG. PROM I.D. SENDER PUMP (SCAN) P/N LABEL (SCAN) P/N P/N ------ ---- ----- ------- --- ---- A 87 AUTO 2692 16143575 ATBX 3541 25093744 25115764 A 87 AUTO 2772 16143575 ATBX 3541 25093744 25115764 A 87 AUTO 9512 16143575 ATBX 3541 25093744 25115764 A 88 AUTO 2712 16143545 ATBM 3461 25093744 25115764 A 88 AUTO 6372 16143545 ATBM 3461 25093744 25115764

(*)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 (P/N 25094266)

Chevrolet Table 2 -- Table 2

VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW NEW MODEL PROM I.D. NEW PROM PROM PROM I.D. CARLINE YEAR TRANS. (scanner) PKG. P/N LABEL (scanner) ------- ---- ----- --------- --------- ------ --------- A 87 AUTO 1212 16143575 ATBX 3541 A 87 AUTO 2692 16143460 ATCB 3581 A 87 AUTO 2772 16143460 ATCB 3581 A 87 AUTO 5392 16143575 ATBX 3541 A 87 AUTO 9512 16143460 ATCB 3581 A 88 AUTO 2712 16143465 ATBN 3471 A 88 AUTO 6372 16143465 ATBN 3471 A 88-89 AUTO 1532 16143545 ATBM 3461 A 88-89 AUTO 5132 16143545 ATBM 3461 A 88-89 AUTO 5932 16143545 ATBM 3461

PONTIAC ONLY.

Pontiac Table 1- Table 1

VEHICLE CONFIGURATION REQUIRED PARTS

CUR.

PROM NEW PROM NEW PROM FUEL FUEL I.D. PKG. PROM I.D. SENDER PUMP CAR M/Y TRANS (SCAN) P/N LABEL (SCAN) P/N P/N --- --- ----- ------ ---- ----- ------ ---- ---- A 87 AUTO 2692 16143575 ATBX 3541 25093744 25115764 A 87 AUTO 2772 16143575 ATBX 3541 25093744 25115764 A 87 AUTO 9512 16143575 ATBX 3541 25093744 25115764 A 88 AUTO 2712 16143545 ATBM 3461 25093744 25115764 A 88 AUTO 6372 16143545 ATBM 3461 25093744 25115764 A 87 AUTO 9512 16143575 ATBX 3541 25093744 25115764 N 87 AUTO 1272 16143457 ATBU 3521 25092778 25115925 N 87 AUTO 9532 16143457 ATBU 3521 25092778 25115925 N 87 MAN 1282 16143452 ATBR 3491 25092778 25115925 N 87 MAN 9542 16143452 ATBR 3491 25092778 25115925 P 87-88 AUTO 2672 16143570 ATBW 3531 25093526 25115764 P 87-88 AUTO 6032 16143570 ATBW 3531 25093526 25115764 P 87-88 AUTO 9552 16143570 ATBW 3531 25093526 25115764 P 87-88 MAN 2682 16143455 ATBT 3511 25093526 25115764 P 87-88 MAN 9562 16143455 ATBT 3511 25093526 25115764

(*) 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 (P/N 25094266).

Pontiac Table 2 -- Table 2

VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW NEW MODEL PROM I.D. NEW PROM PROM PROM I.D. CARLINE YEAR TRANS. (scanner) PKG. P/N LABEL (scanner) ------- ---- ------ --------- -------- ----- --------- A 87 AUTO 1212 16143575 ATBX 3541 A 87 AUTO 2692 16143460 ATCH 3581 A 87 AUTO 2772 16143460 ATCB 3581 A 87 AUTO 5392 16143575 ATBX 3541 A 87 AUTO 9512 16143460 ATCB 3581 A 88 AUTO 2712 16143465 ATBN 3471 A 88 AUTO 6372 16143465 ATBN 3471 A 88-89 AUTO 1532 16143545 ATBM 3461 A 88-89 AUTO 5132 16143545 ATBM 3461 A 88-89 AUTO 5932 16143545 ATBM 3461

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

P 87-88 AUTO 1512 16143570 ATBW 3531 P 87-88 AUTO 2672 16143459 ATCA 3571 P 87-88 AUTO 5372 16143570 ATBW 3531 P 87-88 AUTO 6032 16143459 ATCA 3571 P 87-88 AUTO 9552 16143459 ATCA 3571 P 87-88 MAN l522 16143455 ATBT 3511 P 87-88 MAN 2682 16143453 ATBS 3501 P 87-88 MAN 5382 16143455 ATBT 3511 P 87-88 MAN 9562 16143453 ATBS 3501

OLDSMOBILE ONLY.

Oldsmobile Table 1 -- Table 1

VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT

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

N 87 AUTO A 1272 16143457 ATHU 3521 25092778 25115925 N 87 AUTO D 1272 16143457 ATHU 3521 25092769 25115925 N 87 AUTO D 9532 16143457 ATBU 3521 25092769 25115925 N 87 AUTO A 1272 16143457 ATBU 3521 25092778 25115925 N 87 AUTO A 9532 16143457 ATBU 3521 25092778 25115925 N 87 MAN D 1282 16143452 ATBR 349i 25092769 25115925 N 87 MAN A 1282 16143452 ATBR 3491 25092778 25115925 N 87 MAN D 9542 16143452 ATBR 3491 25092769 25115925 N 87 MAN A 9542 16143452 ATBR 3491 25092778 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 (P/N 25094266).

(**) Note: D = Digital gauges A = Analog gauges

Oldsmobile Table 2 -- Table 2

VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW NEW

MODEL PROM I.D. NEW PROM PROM PROM I.D. CARLINE YEAR TRANS (scanner) 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

(*) Note: Only applicable to vehicles equipped with 215/60 R-14 tires (RPO QMB)

BUICK ONLY.

Buick Table 1 -- Table 1.

VEHICLE CONFIGURATION REQUIRED PARTS

CURRENT NEW (**) PROM NEW NEW PROM FUEL FUEL INST. I.D. PROM PROM I.D. SENDER PUMP CAR M/Y TRANS CLUSTER (SCAN) PKG.P/N LABEL (SCAN) P/N P/N --- --- ----- ------- ------ ------- ----- ------ ---- ---- A 87-88 AUTO D or A 2702 16143580 ATBY 3551 25093744 25115764 A 87-88 AUTO D or A 2782 16143580 ATBY 3551 25093744 25115764 A 87-88 AUTO D or A 9522 16143580 ATBY 3551 25093744 25115764 N 87 AUTO A 1272 16143457 ATBU 3521 25092778 25115925 N 87 AUTO D 1272 16143457 ATBU 3521 25092769 25115925 N 87 AUTO D 9532 16143457 ATBU 3521 25092769 25115925 N 87 AUTO A 9532 16143457 ATBU 3521 25092778 25115925 N 87 MAN D 1282 16143452 ATBR 3491 25092769 25115925 N 87 MAN A 1282 16143452 ATBR 3491 25092778 25115925 N 87 MAN D 9542 16143452 ATBR 3491 25092769 25115925 N 87 MAN A 9542 16143452 ATBR 3491 25092778 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 (P/N 25094266).

Note: D = Digital gauges

A = Analog gauges

Buick Table 2 --

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-RI4 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.