Inspection Procedure 6

INSPECTION PROCEDURE 6: Hard Starting

COMMENT

- 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.
- Dirtiness around throttle valve.
- Malfunction of the EGR valve.

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. Measure the battery positive voltage.

(1)Measure the battery positive voltage during cranking.

- The voltage is 8 volts or more.

Q. Does the voltage remain greater than 8 volts while the engine is cranked?

YES Go to Step 2.
NO Battery Check.
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 the "LOCK" (OFF) position.

Q. Is any 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.





(1)Turn the ignition switch to the "ON" position.
(2)Check the following items in the actuator test. Refer to Actuator Test Reference Table Actuator Test Reference Table.
1. Item 9: 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 MB991958, 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 Data List Reference Table.
2. Item 6: Engine Coolant Temperature Sensor.
(3)Turn
the ignition switch 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. Inspection of throttle body (throttle valve area) for dirtiness.

Q. Is the throttle valve area dirty?

YES Refer to On-vehicle service - Clean the throttle valve area Throttle Body Cleaning.
NO Go to Step 6.
STEP 6. 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 7.
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 7. Check the left bank injector.





(1)Disconnect the left bank injector connector B-25, B-26, B-29.





(2)Measure the resistance between each injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 13.5ohms [at 20°C (68°F)]

Q. Is the measured resistance between 10.5 and 13.5 ohms [at 20°C (68°F)]?

YES Go to Step 8.

NO Replace the faulty injector. Then confirm that the malfunction symptom is eliminated.

STEP 8. Check the right bank injector resistance at intermediate connector B-31.





(1)Disconnect the intermediate connector B-31.





(2)Measure the resistance between each male connector side terminal.
3. Measure the resistance between terminal No. 9 and No. 5 at No. 1 cylinder injector.

4. Measure the resistance between terminal No. 9 and No. 10 at No. 3 cylinder injector.

5. Measure the resistance between terminal No. 9 and No. 4 at No. 5 cylinder injector.

- Resistance should be between 10.5 and 13.5 ohms [at 20°C (68°F)].

Q. Is the measured resistance between 10.5 and 13.5 ohms [at 20°C (68°F)]?

YES Go to Step 11.

NO Go to Step 9.

STEP 9. 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 8.





(3)Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 13.5ohms [at 20°C (68°F)]

Q. Is the measured resistance between 10.5 and 13.5 ohms [at 20°C (68°F)]?

YES Go to Step 10.

NO Replace the injector. Then confirm that the malfunction symptom is eliminated.

STEP 10. Check harness connector B-01 or B-03 or B-04 at right bank injector for damage.





(1)Check the injector connector, which deviated from the standard value listed in Step 8.

Q. Is the harness 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. Harness Connector Inspection.
Then confirm that the malfunction symptom is eliminated.

STEP 11. Check harness connector B-31 at the intermediate connector for damage.





Q. Is the harness connector in good condition?

YES Go to Step 12.

NO Repair or replace it. Harness Connector Inspection.
Then confirm that the malfunction symptom is eliminated.

STEP 12. Check harness connector B-25, B-26, B-29 at the left bank injector for damage.





Q. Is the harness connector in good condition?

YES Go to Step 13.

NO Repair or replace it. Harness Connector Inspection.
Then confirm that the malfunction symptom is eliminated.

STEP 13. Check the harness connector B-22 at the ECM [M/T] or PCM [A/T] for damage.





Q. Is the harness connector in good condition?

YES Go to Step 14.

NO Repair or replace it. Harness Connector Inspection.
Then confirm that the malfunction symptom is eliminated.

STEP 14. Check for harness damage between injector connector and ECM [M/T] or PCM [A/T] connector.









(1) 6. Check the harness wire between injector connector B-01 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 153) at No. 1 cylinder injector.

7. Check the harness wire between injector connector B-29 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 146) at No. 2 cylinder injector.

8. Check the harness wire between injector connector B-03 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 140) at No. 3 cylinder injector.

9. Check the harness wire between injector connector B-26 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 139) at No. 4 cylinder injector.

10. Check the harness wire between injector connector B-04 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 133) at No. 5 cylinder injector.

11. Check the harness wire between injector connector B-25 (terminal No. 2) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 127) at No. 6 cylinder injector.

Q. Is the harness wire in good condition?

YES
Check the following items, and repair or replace the defective items.
12. Check the ignition coil and spark plugs.
13. Check if the injectors are clogged.
14. Check the compression pressure.
15. 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.