Inspection Procedure 7

COMMENT
- In such cases, the cause is usually either weak spark, improper air-fuel mixture or low compression.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the ignition system.
- Malfunction of the injector system.
- Poor fuel quality. (Contamination)
- Poor compression.

DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)

STEP 1. Check the battery positive voltage.
1. Measure the battery positive voltage during cranking.
- The voltage is 8 volts or more.

If the voltage should be 8 volts or more, go to Step 2. If the voltage is less than 8 volts, check the battery. Refer to Battery - Battery check. Then confirm that the malfunction symptom is eliminated.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Read the DTC.

If DTC is not output, go to Step 3.

If DTC is output, refer to Diagnostic Trouble Code Chart.




STEP 3. Using scan tool MB991502, check data list and actuator test.
1. Check the following items in the actuator test.
Refer to Actuator Test Reference Table.
a. Item 07: Fuel Pump.

2. Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 21: Engine Coolant Temperature Sensor.
b. Item 18: Ignition Switch-ST

If the checks above meet the specifications, go to Step 4. If the checks above do not meet the specifications, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 4. Check the ignition timing.
1. Check the ignition timing at cranking.

Standard value: 5° ± 3°

If within specifications, go to Step 5.

If not within specifications, check that the crankshaft position sensor and timing belt cover are in the correct position. Then check that the malfunction is eliminated.




STEP 5. Check the left bank injector.
1. Disconnect the left bank injector connector.




2. Measure the resistance between each injector side connector terminals 1 and 2.

Standard value: 13 - 16 ohms [at 20°C (68°F)]

If within specifications, go to Step 6.

If not within specifications, replace the injector. Then check the malfunction is eliminated.




STEP 6. Check injector intermediate connector B-48 at the right bank injector.
1. Disconnect the injector intermediate harness connector.




2. Measure the resistance between injector side connector terminals 1 and 2 (No.1 injector), 1 and 3 (No.3 injector), 1 and 4 (No.5 injector).

Standard value: 13 - 16 ohms [at 20°C (68°F)]

If within specifications, go to Step 9.

If not within specifications, go to Step 7.




STEP 7. Check the right bank injector.
1. Remove the intake manifold.
2. Disconnect the injector connector, which deviates from the standard value at Step 6.




3. Measure the resistance between injector side connector terminals 1 and 2.

Standard value: 13 - 16 ohms [at 20°C (68°F)]

If within specifications, go to Step 8.

If not within specifications, replace the injector.
Then check the malfunction is eliminated.




STEP 8. Check harness connector B-01 or B-05 or B-26 at the right bank injector for damage.
1. Check the injector connector, which deviated from the standard value listed in Step 6.

If harness connector is in good condition, repair the harness wire between the injector connector and injector intermediate harness connector. Then check the malfunction is eliminated.

If harness connectors is damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.




STEP 9. Check harness connector B-48 at the injector intermediate connector B-48 for damage.
If harness connectors B-48 is in good condition, go to Step 10.

If harness connectors B-48 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then check that the malfunction is eliminated.




STEP 10. Check harness connector B-02, B-06, B-25 at the left bank injector for damage.
If harness connectors B-02, B-06, B-25 are in good condition, go to Step 11.

If harness connectors B-02, B-06, B-25 are damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.




STEP 11. Check the harness connectors C-51 at the ECM or harness connector C-52 at the PCM for damaged.
If harness connectors C-51 or C-52 are in good condition, go to Step 12.

If harness connectors C-51 or C-52 are damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.

STEP 12. Check the harness wire between injector connectors B-01 B-02, B-05, B-25, B-26 and ECM connector C-51 or PCM connector C-52 .
If the wire between injector connectors B-01, B-02, B-05, B-06, B-25, B-26 and ECM connector C-51 or PCM connector C-52 are not damaged, go to Step 13.

If the wire between injector connectors B-01, B-02, B-05, B-06, B-25, B-26 and ECM connector C-51 or PCM connector C-52 are damaged, repair it. Then check the malfunction is eliminated.

STEP 13. 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 in the injectors are clogged.
c. Check the compression pressure.
d. Check if the foreign materials (water, kerosene, etc.) got into fuel.

Then check the malfunction is eliminated.