Engine - Stalls After Hot Restart/Cold Start/Hesitation
88olds04NUMBER: 87-T-59A
CORP. REF. NO.: 836502
DATE: February 1988
SECTION: 6E
SUBJECT ENGINE STALL AFTER HOT RESTART/COLD
START, AND COLD ENGINE HESITATION
1987 CUTLASS CIERA AND FIRENZA
MODELS/YEARS MODELS EQUIPPED WITH THE 2.8L ENGINE
(VIN CODE W)
This bulletin 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 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 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 post 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. A 5- speed manual transxle may also experience a hesitation during acceleration, during cold operation (40 to 70 degrees F.) 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 mass airflow sensor are secure.
NOTICE: LOOSE/POOR ELECTRICAL CONNECTIONS AT ALL SENSORS AND ECM METRIPAK CONNECTORS CAN BE A PROBLEM ANYWHERE ON THE ENGINE. INTERMITTENT CONNECTION CAN PRODUCE STALLING.
3. Verify that there are no engine vacuum looks 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
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.