Inspection Procedure 11
INSPECTION PROCEDURE 11When the engine is cold, it stalls at idle (die out)
COMMENT
- In such cases as the above, the air/fuel mixture may be inappropriate when the engine is cold.
TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the IAC system.
- Malfunction of the throttle body.
- Malfunction of the injector system.
- Malfunction of the ignition system.
DIAGNOSIS
Required Special Tools: MB991502: Scan Tool
STEP 1. Check if the battery terminal is disconnected.
Has the battery terminal been disconnected lately? If no, go to Step 2.
If yes, start the engine and let it run at idle for approximately 10 minutes after engine warm-up. Then, if a malfunction occurs, go to Step 2.
STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).
CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.
If DTC is not output, go to Step 3.
If DTC is output, refer to Inspection Chart for Diagnostic Trouble Code.
STEP 3. Checking by operating the accelerator pedal.
(1) Does the engine stall right after the accelerator pedal is released.
If the engine does not stall, go to Step 4.
If the engine stalls easily, carry out the following cleaning or adjustment.
- Clean the throttle valve area.
- Check and adjust the fixed SAS.
Then confirm that the malfunction symptom is eliminated.
STEP 4. Check the engine idling.
If the idling state after the engine has been warmed up is correct, go to Step 5.
If the idling state after the engine has been warmed up is not correct, refer to INSPECTION PROCEDURE 8 - Unstable Idle (Rough Idle, Hunting).
STEP 5. Check the idle air control (IAC) motor operation sound.
NOTE: Disconnecting the engine coolant temperature sensor connector and connecting the harness side of the connector to another engine coolant temperature sensor that is at 20°C (68°F) or below is also okay.
(1) Check that the engine coolant temperature is 20°C (68°F) or below.
(2) Check the operation sound of the IAC motor can be heard after the ignition is switched "ON" (but without starting the engine).
- An operation sound should be heard.
If a sound is heard, go to Step 6.
If no sound is heard, refer to DTC P0505 Idle Control System Malfunction.
STEP 6. Check the injector for operation sound.
(1) Using a stethoscope or long blade screwdriver, check the operation sound ("tick-tick-tick") of injectors during idling or during cranking.
- An operation sound is heard.
If a sound is heard, go to Step 7.
If no sound is heard, refer to DTC P0201, P0202, P0203, P0204 - Injector Circuit Malfunction.
STEP 7. Using scan tool MB991502, check data list.
CAUTION: To prevent damage to the scan/ tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.
(1) Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 26: Closed Throttle Position Switch.
b. Item 21: Engine Coolant Temperature Sensor.
If the checks above meet the specifications, go to Step 8. If the checks above do not meet the specifications, repair or replace. Then confirm that the malfunction symptom is eliminated.
STEP 8. Chock the fuel pressure.
Refer to Fuel Pressure Test.
If correct, go to Step 9.
If incorrect, repair or replace. Then confirm that the malfunction symptom is eliminated.
STEP 9. Check the ignition timing.
Refer to On-vehicle Service.
If within specifications, go to Step 10.
If not within specifications, check and repair the crankshaft position sensor. Check that the timing belt cover is in the correct position. Then confirm that the malfunction symptom is eliminated.
STEP 10. Check the following items.
(1) Check the following items and repair or replace the defective items.
a. Check the ignition coil, spark plugs, spark plug cables.
b. Check compression.
c. Check the engine oil viscosity.
Then confirm that the malfunction symptom is eliminated.