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 fuel pump system.

- Malfunction of the ignition system.

- Malfunction of the injector system.

- Poor compression

- Malfunction of the EGR system

- Contaminated fuel.

- Malfunction of the ECM.

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 EGR valve sounds during initialization.

Q. Is the initialization sound heard in the EGR valve?

YES Go to Step 2.
NO EGR Valve (Stepper Motor) 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 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.
1. Item 1: Power Supply Voltage (at Cranking)

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 4.
NO Repair or Replace. Then confirm that the malfunction symptom is eliminated.
STEP 4. 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.
3. Item 9: Fuel Pump.

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the actuator 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 for installed conditions of the timing belt. Then confirm that the malfunction symptom is eliminated.
STEP 6. Check the fuel pressure.

Refer to On-vehicle Service - Fuel Pressure Test Testing and Inspection.

Q. Is the fuel pressure normal?

YES Go to Step 7.
NO
Check the following items, and repair or replace the defective items.
- Insufficient fuel pump discharge.

- Fuel pump filter clogged.

STEP 7. Check the left bank injector resistance.

(1)Disconnect the left bank injector connector B-115, B-116, B-120.





(2)Measure the resistance between each injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 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 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-21.

(1)Disconnect the intermediate connector B-21.





(2)Measure the resistance between each male connector side terminal.
4. Measure the resistance between terminal No. 6 and No. 7 at No. 1 cylinder injector.

5. Measure the resistance between terminal No. 6 and No. 8 at No. 3 cylinder injector.

6. Measure the resistance between terminal No. 6 and No. 9 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 resistance.

(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 - 13.5 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 10.

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

STEP 10. Check harness connector B-101, B-103, B-104 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-21 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-10 at ECM and harness connector B-115, B-116, B-120 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 for harness damage between injector connector and ECM connector.

(1)Disconnect the injector connector and ECM connector.





(2)Measure the resistance between injector connector and ECM connector.
7. Injector connector B-101 (terminal No. 2) and ECM connector B-10 (terminal No. 2) at No. 1 cylinder injector.

8. Injector connector B-120 (terminal No. 2) and ECM connector B-10 (terminal No. 3) at No. 2 cylinder injector.

9. Injector connector B-103 (terminal No. 2) and ECM connector B-10 (terminal No. 18) at No. 3 cylinder injector.

10. Injector connector B-116 (terminal No. 2) and ECM connector B-10 (terminal No. 19) at No. 4 cylinder injector.

11. Injector connector B-104 (terminal No. 2) and ECM connector B-10 (terminal No. 50) at No. 5 cylinder injector.

12. Injector connector B-115 (terminal No. 2) and ECM connector B-10 (terminal No. 51) at No. 6 cylinder injector.

Q. Is the measured resistance less than 2 ohms?

YES Go to Step 14.

NO Repair it. Then confirm that the malfunction symptom is eliminated.

STEP 14. Check the ignition system.

(1)Connect the timing light to terminal No. 3 of the ignition coil connector B-01, B-04, B-05, B-15, B-18 or B-19 in order.

(2)Crank the engine.

- The timing light flashes.

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Does the timing light flash?

YES Go to Step 15.
NO Refer to INSPECTION PROCEDURE 24 - Ignition Circuit System Inspection Procedure 26.
STEP 15. Check the spark plugs.

Procedures.

Q. Are there any abnormalities?

YES Replace the spark plug. Then confirm that the malfunction symptom is eliminated.
NO Go to Step 16.
STEP 16. Check the ignition coil.

(1)Remove the intake manifold.

(2) Testing and Inspection.

Q. Are there any abnormalities?

YES Replace the ignition coil. Then confirm that the malfunction symptom is eliminated.
NO Go to Step 17.
STEP 17. Check the compression pressure.

Testing and Inspection.

Q. Is the compression pressure normal?

YES
Check the following items, and repair or replace the defective items.
13. Check if fuel is contaminated.

14. Check if the injectors are clogged.
Then
confirm that the malfunction symptom is eliminated.

NO Repair it. Then confirm that the malfunction symptom is eliminated.