OCCASIONAL ENGINE STALL (DIAGNOSTIC CHECK/NEW MEMCAL)

Subject: OCCASIONAL ENGINE STALL (DIAGNOSTIC CHECKS AND NEW SERVICE MEMCAL)

Models Affected: 1988 6000 AWD W/3.1 AND 1989 6000 AND GRAND PRIX W/2.8L

This bulletin cancels and replaces bulletin 89-6-31B issued 3190. This bulletin has been revised to update the part number for the 1988 6000 STE model and to include PIN's for 1989 6000 w/Federal Emission and MD9 (automatic transmission).

Some customers driving the following cars; - 1989 6000 and Grand Prix models with a 2.8L engine (VIN Code W) - 1988 6000 All-Wheel-Drive model with a 3.1L engine (VIN Code T)

may comment concerning any of the following:

A cold start stall, A tip-in hesitation, or A decel stall

If a customer comment concerning an occasional engine stall or a drive hesitation is received, then complete the following:

1. Perform diagnostic checks, per Section 6E of the Service Manual and replace any defective components.

Proceed to Step #2 only if diagnostic checks uncover no cause for the customer comments.

2. Install a new MEMCAL, which may be obtained from GMSPO (reforence the attached service part number chart).

IMPORTANT: The following procedure must be completed when removing and installing a 60 degree V6 Engine Control Module (ECM) MEMCAL (Reference 89-6-9A issued 12/88).

a). Disconnect the battery. b). Remove current MEMCAL and install a new service MEMCAL. c). Restore the battery power and place air conditioning controls (if equipped) in the "off" position. d). Firmly apply the parking brake and block the drive wheels. Start the engine, and shift the transaxle to "drive" for automatics or "neutral" for manuals. e). Allow the engine to run until the engine cooling fan has cycled once, or a maximum of 10 minutes. f). Turn the ignition key to the "off" position for at least 5 seconds. g). Start the engine, and shift the transaxle to "drive" for automatics or "neutral" for manuals. h). Allow engine to run for at least 5 minutes.

MEMCAL CHART

EMISSION SCANNER SERVICE YEAR MODEL SYSTEM TRANS. I.D. MEMCAL P/N ------ ---------- -------- ------ ------ ----------- 1989 Grand Prix FED MG2 7461 16147315 1989 Grand Prix CAL. MG2 7471 16147316 1989 Grand Prix FED ME9 8151 16138169 1989 Grand Prix CAL ME9 8141 16138164

1989 6000 FED MD9 8021 16138174 1989 6000 CAL MD9 8031 16138179 1989 6000 FED ME9 8041 16138184 1989 6000 CAL ME9 8051 16138188

1988 6000 FED MD9 2401 16150336

Remarks: 6000 STE Model (Special Touring Edition) Y88 (LHO Engine)

Parts are currently available from GMSPO.

Labor Operation Number: T1426 Labor Time .7 Hours

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.