Inspection Procedure 11
INSPECTION PROCEDURE 11: When the Engine Is Hot, It Stalls at Idle (die out)
COMMENT
- In cases such as the above, the ignition system, air/fuel mixture, electronic control throttle valve system or compression pressure may be faulty. In addition, if the engine suddenly stalls, the cause may also be a connector damage.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of the ignition system.
- Malfunction of air/fuel ratio control system.
- Malfunction of the electronic control throttle valve system.
- Malfunction of the EGR valve.
- Vacuum leak.
- Improper connector contact.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A
STEP 1. Check if the battery terminal is disconnected.
Q. Has the battery terminal been disconnected lately?
YES Start the engine and let it run at idle for approximate 10 minutes after engine warm up. Then, if a malfunction occurs, go to step 2.
NO Go to Step 2.
STEP 2. Using scan tool MB991958, read the diagnostic trouble code
(DTC).
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool MB991958.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Read the DTC.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Refer to Diagnostic Trouble Code Chart Multiport Fuel Injection (MFI).
NO Go to Step 3.
STEP 3. Using scan tool MB991958, check actuator test items 1, 2, 3, 4: Injector.
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool MB991958.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Check following items in the actuator test. Refer to Actuator Test Reference Table Actuator Test Reference Table.
1. Item 1, 2, 3, 4: Injector.
(4)Turn
the ignition switch to the "LOCK" (OFF) position.
Q. Are they operating properly?
YES Go to Step 4.
NO Refer to DTC P0201 - Injector Circuit-cylinder 1 P0201, DTC P0202 - Injector Circuit-cylinder 2 P0202, DTC P0203 - Injector Circuit-cylinder 3 P0203, DTC P0204 - Injector Circuit-cylinder 4 P0204.
STEP 4. Checking by depressing and releasing the accelerator pedal.
Q. Does the engine stall right after the accelerator pedal is released?
YES Refer to On-vehicle Service - Throttle Body (Throttle Valve Area) Cleaning Throttle Body Cleaning.
NO Go to Step 5.
STEP 5. Engine stall reproduction test.
Q. Is it easy to reproduce the engine stall?
YES Go to Step 6.
NO
Check if the following signals change suddenly by wiggling the circuit harness and connectors.
2. Crankshaft position sensor signal.
3. Mass airflow sensor signal.
4. Injector drive signal.
5. Primary and secondary ignition signal.
6. Fuel pump drive signal.
7. ECM[ M/T] or PCM[ A/T] power supply voltage.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 6. Using scan tool MB991958, check data list.
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool MB991958.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Check the following items in the data list. Refer to Data List Reference Table Data List Reference Table.
8. Item 5: Intake Air Temperature Sensor.
9. Item 6: Engine Coolant Temperature Sensor.
10. Item 83: Power Steering Pressure Switch.
11. Item 31: EGR valve (stepper motor).
12. Item 13: Throttle position sensor (main).
13. Item AC: Cylinder 1, 4 Heated Oxygen Sensor (front)
14. Item AD: Cylinder 1, 4 Heated Oxygen Sensor (rear)
15. Item AE: Cylinder 2, 3 Heated Oxygen Sensor (front)
16. Item AF: Cylinder 2, 3 Heated Oxygen Sensor (rear)
17. Item BB: Barometric Pressure Sensor
(4)Turn
the ignition switch to the "LOCK" (OFF) position.
Q. Are they operating properly?
YES Go to Step 7.
NO Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 7. Using scan tool MB991958, check data list.
(1)Turn the ignition switch to the "ON" position.
(2)Check the following items of the data list. Refer to Data List Reference Table Data List Reference Table.
18. Item AC: Cylinder 1, 4 Heated Oxygen Sensor (front).
19. Item AE: Cylinder 2, 3 Heated Oxygen Sensor (front).
- Fluctuates between 0 - 0.4 volt and 0.6 - 1.0 volt while idling after the engine has been warmed.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Are they operating properly?
YES Go to Step 9.
NO Go to Step 8.
STEP 8. Check the fuel pressure.
Refer to On-vehicle Service - Fuel Pressure Test Testing and Inspection.
Q. Is the fuel pressure normal?
YES
Check the following items, and repair or replace the defective items.
20. Vacuum leak.
- Broken intake manifold gasket.
- Broken air intake hose.
- Broken vacuum hose.
- Positive crankcase ventilation valve does not operate.
21. Injector clogged.
Then confirm that the malfunction symptom is eliminated.
NO Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 9. Check the ignition timing.
Testing and Inspection.
Q. Is the ignition timing normal?
YES
Check the following items, and repair or replace the defective items.
22. Check the ignition coil and spark plugs.
23. Check if the injectors are clogged.
24. Check compression pressure.
25. Check if the foreign materials (water, kerosene, etc.) got into fuel.
26. Check the EGR valve.
Then confirm that the malfunction symptom is eliminated.
NO Check that the crankshaft position sensor and timing cover are in the correct position. Then confirm that the malfunction symptom is eliminated.