ENG. STALL AFTER HOT RESTART/ COLD START AND COLD ENG. HES.

VEHICLES AFFECTED: 1987-1988 A,W,J,L W/2.8L (VIN W)

Some 1987 A, J, or L models and 1988 L or W models equipped with a 2.8L V-6 engine may experience a cold start stall, a stall after start with a warmed-up engine or a stall during deceleration. A 5-speed manual transmission L or J car may also experience a hesitation during acceleration primarily when the engine is cold (ambient temperatures of 40 to 70 degrees Fahrenheit). This hesitation may also be experienced during transmission gear shifts.

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 pas 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 loss of fuel pressure, or loose electrical connections at the ignition coil and/or the mass airflow sensor.

Customer comments may be repaired as follows:

1. Perform normal service procedures as outlined in the shop manual for the repair of engine stall or hesitation.

2. Verify that all electrical connections such as at the ignition coil and mass 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 Product Service Bulletin 87-628-109.

6. Measure the minimum idle speed and throttle position, and adjust to specifications if required. (Reference Product Service Bulletin 87-628-109).

*7. Measure the Throttle Position Sensor (TPS) voltage and adjust to 0.62-0.67 volts, if required.

8. Replace the ECM MEMCAL, (see chart) using the following installation.

a) Disconnect battery power. b) Install new ECM MEMCAL 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: DO NOT REPLACE THE MEMCAL AND RETURN THE VEHICLE TO THE CUSTOMER WITHOUT PROPERLY COMPLETING THE PREVIOUS SERVICE INSTRUCTIONS (ITEMS 1-7).

WARRANTY INFORMATION

Use applicable labour time and operation numbers. TEXT ZONE

MODEL IDENTIFICATION P.S.B. 87-628-103

THE MAKE IS IDENTIFIED BY VIN POSITION # 3. EG. 1 = CHEV 2 = PONTIAC 3 = OLDS 4 = BUICK

THE BODY TYPE IS IDENTIFIED BY VIN POSITION #4. EG. A = A BODY J = J BODY L = L BODY

THE SERIES IS IDENTIFIED BY VIN POSITION #5. EG. W = CELEBRITY

THE BODY STYLE IS IDENTIFIED BY VIN POSITION #6. EG. 1 = STYLE 11, 27, 37, 47, 57, 97 2 = STYLE 07, 08, 77, 87 3 = STYLE 67 5 = STYLE 19, 23, 33, 6 9 6 = STYLE 68 8 = STYLE 35

EXAMPLES OF MODEL ID A - CARS

FROM THE VIN: 1AW5 = 1AW19 1AW1 = 1AW27 3AJ1 = 3AJ37 4AH8 = 4AH35

ADDITIONAL INFORMATION ON VEHICLE IDENTIFICATION NUMBERS IS OUTLINED IN PRODUCT SERVICE BULLETIN 87-0-103.

1987 MODEL YEAR

TRANSAXLE EMISSION SERVICE L SERIES TRANS. RATIO/CODE SYSTEM MEMCAL P/N SPECIAL OPTION -------- ------ ---------- ------ ---------- ---------------

1LT69 3-SPD AUTO 3.18 FEDERAL 16087162 BASE, AND GT 1LV37 7LT69 TEMPEST

1LT69 5-SPD MAN. 3.61 FEDERAL 16087172 BASE, AND ST 1LV37 7LT69 TEMPEST

A SERIES

1AW19-27 5-SPD MAN. 3.61 FEDERAL 16087148 2AE19 5-SPD MAN. 3.61 FEDERAL 16087148 6000-SE 2AH19 5-SPD MAN. 3.61 FEDERAL 16087148 6000-STE

1AW3 5 5-SPD MAN. 3.61 FEDERAL 16087122 2AE3 5 5-SPD MAN. 3.61 FEDERAL 16087122

1AW19-27 3-SPD AUTO 3.18/7CXC FEDERAL 01228600 2AF19-27 3-SPD AUTO 3.18/7CXC FEDERAL 01228600 2AG19 3-SPD AUTO 3.18/7CXC FEDERAL 01228600

1AW35-2AA35 3-SPD AUTO 3.18/7CXC FEDERAL 01228608 2AE/AF35

1AW19-27 4-SPD AUTO 3.33 FEDERAL 01228604 2AF19-27 4-SPD AUTO 3.33 FEDERAL 01228604 2AG19 4-SPD AUTO 3.33 FEDERAL 01228604

1AW35-2AE/ 4-SPD AUTO 3.33 FEDERAL 01228612 WAGON AF3 5 2AE19 4-SPD AUTO 3.33 FEDERAL 01228612 6000-SE 2AH19 4-SPD AUTO 3.33 FEDERAL 01228612 6000-STE

3AJ/AM19-37 3-SPD AUTO 2.84/7CTC FEDERAL 16087135

3AJ/AM19-37 3-SPD AUTO 3.18/7CXC FEDERAL 01228601 4AH/AL19-27 3-SPD AUTO 3.18/7CXC FEDERAL 01228601

3AJ/AM35 3-SPD AUTO 3.18/7CXC FEDERAL 01228609 4AH/AL35

3AJ/AM19-37 4-SPD AUTO 3.33 FEDERAL 16087075 4AH/AL19-27 4-SPD AUTO 3.33 FEDERAL 16087075

3AJ/AM35 4-SPD AUTO 3.33 FEDERAL 16087057 4AH/AL35

1987 MODEL YEAR

TRANSAXLE EMISSION SERVICE J SERIES TRANS. RATIO/CODE SYSTEM MEMCAL P/N SPECIAL OPTION -------- ------ ---------- ------ ---------- -------------- 1JE/JF27-77 3-SPD AUTO 3.18 FEDERAL 01228533 1JE67-69 1JC/JD/JE35 3-SPD AUTO 3.18 FEDERAL 01228533 WAGON *3JD77

1JE/JF27-77 5-SPD MAN 3.61 FEDERAL 16120949 1JE67-69 1JC/JD/JE35 5-SPD MAN 3.61 FEDERAL 16120949 WAGON *3JD77

1JF27-77 3-SPD AUTO 3.18 FEDERAL 01228535 Z24

1JF27-77 5-SPD MAN 3.61 FEDERAL 16120954 Z24

1988 MODEL YEAR

TRANSAXLE EMISSION SERVICE L SERIES TRANS. RATIO/CODE SYSTEM MEMCAL P/N SPECIAL OPTION -------- ------ ---------- ------ ---------- ---------------

1LV37 3-SPD AUTO 3.18 FEDERAL 16087162 BASE, AND GT 1LT69 7LT69 TEMPEST

lLV37 5-SPD MAN 3.61 FEDERAL 16087172 BASE, AND GT lLT69 7LT69 TEMPEST

W SERIES

4WB57/D57 4-SPD AUTO 3.33 FEDERAL 16087003

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.