Inspection Procedure 7
Hard StartingCOMMENT
- In cases such as the above, 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.
Q: Is the voltage normal?
YES: Go to Step 2.
NO: Refer to Battery Battery check.
STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 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 is output?
YES: Refer to Diagnostic Trouble Code Chart.
NO: Go to Step 3.
STEP 3. Using scan tool MB991502, check actuator test.
1. Turn the ignition switch to the "ON" position.
2. Check the following items in the actuator test. Refer to Actuator Test Reference Table.
a. Item 07: Fuel Pump.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the actuator operating properly?
YES: Go to Step 4.
NO: Repair or Replace. Then confirm that the malfunction symptom is eliminated.
STEP 4. Using scan tool MB991502, check data list.
1. Turn the ignition switch the "ON" position.
2. Check the following items in the data list. Refer to Data List Reference Table.
a. Item 21: Engine Coolant Temperature Sensor.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: Go to Step 5.
NO: Repair or Replace. Then confirm that the malfunction symptom is eliminated.
STEP 5. Check the ignition timing.
1. Check the ignition timing at cranking.
Standard value: 5° BTDC ± 3°
Q: Is the ignition timing normal?
YES: Go to Step 6.
NO: Check that the crankshaft position sensor and timing belt cover are in the correct position. Then confirm that the malfunction symptom is eliminated.
STEP 6. Check the left bank injector.
1. Disconnect the left bank injector connector B-02, B-06, B-25.
2. Measure the resistance between each injector side connector terminals 1 and 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the resistance standard value?
YES: Go to Step 7.
NO: Replace the faulty injector. Then confirm that the malfunction symptom is eliminated.
STEP 7. Check the right bank injector resistance at injector intermediate connector B-118.
1. Disconnect the injector intermediate connector B-118.
2. Measure the resistance between each male connector side terminal.
a. Measure the resistance between terminal 1 and 2 when measuring No.1 cylinder injector.
b. Measure the resistance between terminal 1 and 3 when measuring No.3 cylinder injector.
c. Measure the resistance between terminal 1 and 4 when measuring No.5 cylinder injector.
Resistance should be between 13 and 16 Ohms at 20 °C (68 °F)].
Q: Is the resistance normal?
YES: Go to Step 10.
NO: Go to Step 8.
STEP 8. Check the right bank injector.
1. Remove the intake manifold.
2. Disconnect the right bank injector connector, which deviates from the standard value at Step 7.
3. Measure the resistance between injector side connector terminals 1 and 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the resistance standard value?
YES: Go to Step 9.
NO: Replace the injector. Then confirm that the malfunction symptom is eliminated.
STEP 9. Check connector B-01 or B-05 or B-26 at right bank injector for damage.
1. Check the injector connector, which deviated from the standard value listed in Step 7.
Q: Is the connector in good condition?
YES: Repair harness wire between injector intermediate connector and right bank injector connector because of harness damage. Then confirm that the malfunction symptom is eliminated.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 10. Check connector B-118 at the injector intermediate connector for damage.
Q: Is the connector in good condition?
YES: Go to Step 11.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 11. Check connector B-02, B-06, B-25 at the left bank injector for damage.
Q: Is the connector in good condition?
YES: Go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 12. Check the connector C-111 at the ECM
Q: Is the connector in good condition?
YES: Go to Step 13.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 13. Check for harness damage between injector connector and PCM connector.
a. Check the harness wire between injector connector B-01 terminal 2 and ECM connector C-111 terminal 1
b. Check the harness wire between injector connector B-02 terminal 2 and ECM connector C-111 terminal 9
c. Check the harness wire between injector connector B-05 terminal 2 and ECM connector C-111 terminal 24
d. Check the harness wire between injector connector B- 06 terminal 2 and ECM connector C-111 terminal 2
e. Check the harness wire between injector connector B- 26 terminal 2 and ECM connector C-111 terminal 10
f. Check the harness wire between injector connector B- 25 terminal 2 and ECM connector C-111 terminal 25
Q: Is the harness wire in good condition?
YES: Check the following items, and repair or replace the defective items.
a. Check the ignition coil, spark plugs, spark plug cables.
b. Check if the injectors are clogged.
c. Check the compression pressure.
d. Check if the foreign materials (water, kerosene, etc.) got into fuel.
Then confirm that the malfunction symptom is eliminated.
NO: Repair it.Then confirm that the malfunction symptom is eliminated.