ENG. STALL AFTER HOT RESTART COLD START & COLD ENG. HES.

1987 CUTLASS CIERA AND FIRENZA MODELS EQUIPPED WITH THE 2.8L ENGINE (VIN CODE W)

This bulIetin supersedes Dealer Technical Bulletin 87-T-59 which may be discarded. This bulletin has been revised to include the Firenza model.

Some 1987 Cutlass Ciera and Firenza models equipped with a 9.8L V-6 engine may experience a cold start stall, a stall after start with a warmed-up engine or a stall during deceleration.

A repeated stall after hot restart may be caused by residue accumulating inside the throttle body bore, behind the throttle plate, which limits the air flow past the throttle plate in the idle position. The hesitation concern may be due to a lean Electronic Control Module (ECM) fuel calibration. The cold start stall may be due to a lean ECM calibration, low engine idle speeds, the Ioss of fuel pressure, or loose electrical connections at the ignition coil and/or the man airflow sensor. A 5 speed manual transaxle may also experience a hesitation during acceleration, during cold operation (40 to 70 degrees Fahrenheit.) and/or during transaxle gear shifts.

The above customer comments may be repaired as follows:

1. Perform normal service procedures as outlined in the Chassis Service Manual for the repair of engine stall or hesitation.

2. Verify that all electrical connections such as at the ignition coil and man airflow sensor are secure.

NOTICE: LOOSE/POOR ELECTRICAL CONNECTIONS AT ALL SENSORS AND ECM METRI-PAK CONNECTORS CAN BE A PROBLEM ANYWHERE ON THE ENGINE. INTERMITTENT CONNECTION CAN PRODUCE STALLING.

3. Verify that there are no engine vacuum leaks at the manifold absolute pressure (MAP) sensor, positive crankcase ventilation (PCV), exhaust gas recirculation (EGR), or other systems.

4. Verify that the fuel system is functioning properly and has proper fuel pressure.

5. Clean the throttle body bore as specified in May, 1987 Service Guild, page 66.

6. Measure the minimum idle speed and throttle position, and adjust to specification if required.

7. Replace the ECM MEM-CAL (from the list), using the following installation procedure:

CUTLASS CIERA

Model Trans Axle Emission PROM ----- ----- ---- -------- ----

Coupe/Sedan 3 Speed Auto 2.84 (F17) Federal 16087135 California 1228599

3.18 (F75) Federal 1228601 California 1228603

4 Speed Auto 3.33 (GX3) Federal 16087075 California 1228607

Wagon 3 Speed Auto 3.18 (F75) Federal 1228609 California 1228611

4 Speed Auto 3.33 (GX3) Federal 16087057 California 1228615

FIRENZA

Model Trans Axle Emission PROM ----- ----- ---- -------- ----

All 3 Speed Auto 3.18 (F75) Federal 128533 California 1228534

5 Speed Manual 3.61 (FX8) Federal 16120949 California 16120953

a. Disconnect battery power.

b. Install new ECM MEM-CAL calibration.

c. Reconnect battery power.

d. Start vehicle with AC/defroster off and power steering not cramped.

e. Allow vehicle to idle in drive for 6 minutes and until thermostat has opened. This will facilitate learning of base idle.

f. Return vehicle to service.

NOTICE: IT IS INAPPROPRIATE TO REPLACE THE MEM-CAL AND RETURN THE VEHICLE TO THE CUSTOMER WITHOUT PROPERLY COMPLETING THE PREVIOUS SERVICE INSTRUCTIONS (ITEMS 1-6).

Use applicable labor time and operation numbers.

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.