TIP-IN HESITATION, LONG CRANK WHEN COLD AND/OR DETONATION

SUBJECT: TIP-IN HESITATION, SAG, LONG CRANK TIMES WHEN COLD, AND/OR DETONATION

MODELS AFFECTED: 1991-1992 BROUGHAMS WITH 5.0L OR 5.7L TBI ENGINE

Some 1991-1992 Broughams with 5.0L or 5.7L TBI may experience one or more of the following driveability conditions:

1991 Vehicles Only:

o Tip-in sag o Tip-in hesitation o Long crank time when cold

1991-1992 Vehicles:

o Spark detonation

To repair the above conditions a service PROM has been developed and is available from GMSPO.

1991 Vehicles Only:

o Install a new service PROM for the appropriate model as listed below. Refer to Section 6E2-C1 of the appropriate Service Information Manual for proper installation.

Service Service PROM Broadcast Vehicle Engine P/N I.D.* Code ------- ------ ------- ------- --------- D Fed/Cal 5.0 16160477 0531 AXHR D Fed/Cal 5.7 16159963 9971 AXDA D Export (leaded) 5.7 16159983 9984 AXDF

* ECM PROM I.D. can be read with a scan tool connected to the ALDL connector.

1991-1992 Vehicle with Spark Detonation:

- Replace the Electronic Spark Control (ESC) module with P/N 16175099. Refer to Section 6E2-C5 of the appropriate Service Information Manual for proper installation.

NOTE: The PROM does not require replacing on 1992 vehicles.

Parts are currently available from GMSPO.

WARRANTY INFORMATION Operation VEHICLE SERIES -------------------- Number -------------- Operation Description --------- --------------------- C D E J K V ------------------ MEM-CAL - Replace J6364 .4

ESC Module - Replace J4438 .2

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.