MULTIPLE DRIVEABILITY CONCERNS FOR 2.5L ENGINE

Models Affected: 1987-89 6000, GRAND AM AND FIERO

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

Some 1987-89 6000 and Grand Am and 1987-88 Fiero models 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.

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 P

1.6 Hr. 1.7Hr. 1.4Hr.

Pontiac Table 1 -- TABLE 1 -------- (*) VEHICLE CONFIGURATION REQUIRED PARTS --------------------- CUR. PROM NEWPROM NEW PROM FUEL FUEL I.D. PKG. PROM I.D. SENDER Pump M/Y TRANS (SCAN) P/N LABEL (SCAN) P/N P/N --- ----- ------ --- ----- ------ ---- --- 87 6000 AUTO 2692 16143575 ATBX 3541 25093744 25115764 87 6000 AUTO 2772 16143575 ATBX 3541 25093744 25115764 87 6000 AUTO 9512 16143575 ATBX 3541 25093744 25115764 88 6000 AUTO 2712 16143545 ATBM 3461 25093744 25115764 88 6000 AUTO 6372 16143545 ATBM 3461 25093744 25115764

87 GRAND AM AUTO 1272 16143457 ATBU 3521 25092778 25115925 87 GRAND AM AUTO 9532 16143457 ATBU 3521 25092778 25115925 87 GRAND AM MAN 1282 16143452 ATBR 3491 25092778 25115925 87 GRAND AM MAN 9542 16143452 ATBR 3491 25092778 25115925

87-88 FIERO AUTO 2672 16143570 ATBW 3531 25093526 25115764 87-88 FIERO AUTO 6032 16143570 ATBW 3531 25093526 25115764 87-88 FIERO AUTO 9552 16143570 ATBW 3531 25093526 25115764 87-88 FIERO MAN 2682 16143455 ATBT 3511 25093526 25115764 87-88 FIERO 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) ------- ---- ------ ---------- -------- ----- --------- 6000 87 AUTO 1212 16143575 ATBX 3541 6000 87 AUTO 2692 16143460 ATCB 3581 6000 87 AUTO 2772 16143460 ATCB 3581 6000 87 AUTO 5392 16143575 ATBX 3541 6000 87 AUTO 9512 16143460 ATCB 3581 6000 88 AUTO 2712 16143465 ATBN 3471 6000 88 AUTO 6372 16143465 ATBN 3471 6000 88-89 AUTO 1532 16143545 ATBM 3461 6000 88-89 AUTO 5132 16143545 ATBM 3461 6000 88-89 AUTO 5932 16143545 ATBM 3461

GRAND AM 87 AUTO 1272 16143466 ATBP 3481 GRAND AM 87 AUTO 9532 16143466 ATBP 3481 GRAND AM 87 MAN 1282 16143463 ATBL 3451 GRAND AM 87 MAN 9542 16143463 ATBL 3451 GRAND AM 87-88 AUTO 1232 16143457 ATBU 3521 GRAND AM 87-88 AUTO 6402 16143457 ATBU 3521 GRAND AM 87-88 MAN 1242 16143452 ATBR 3491 GRAND AM 87-88 MAN 6412 16143452 ATBR 3491

FIERO 87-88 AUTO 1512 16143570 ATBW 3531 FIERO 87-88 AUTO 2672 16143459 ATCA 3571 FIERO 87-88 AUTO 5372 16143570 ATBW 3531 FIERO 87-88 AUTO 6032 16143459 ATCA 3571 FIERO 87-88 AUTO 9552 16143459 ATCA 3571 FIERO 87-88 MAN 1522 16143455 ATBT 3511 FIERO 87-88 MAN 2682 16143453 ATBS 3501 FIERO 87-88 MAN 5382 16143455 ATBT 3511 FIERO 87-88 MAN 9562 16143453 ATBS 3501

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.