Mitsubishi 380. Manual - part 617

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-560

INSPECTION PROCEDURE 7: 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.

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

DIAGNOSIS

Required Special Tools:

• : Diagnostic Tool (MUT-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 :  Refer to GROUP 54A, Battery 

− Battery check 

P.54A-5

.

STEP 2. Using diagnostic tool , read the diagnostic trouble 
code (DTC).

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool 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 the DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-17

. 

NO :  Go to Step 3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-561

STEP 3. Check for Fuel Pump operation.
(1) Refer to Fuel Pump Operation Check 

P.13A-664

.

Q: Is the actuator operating properly?

YES : Go to Step 4.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

STEP 4. Using diagnostic tool , 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 

P.13A-637

.

a. 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.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-562

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 

P.13A-660

.

NO :  Go to Step 6.

STEP 6. Check the advance ignition timing.
(1)

Check the advance 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-27, B-26, 

B-30.

(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.

AK303075

M

1

2

CONNECTOR: B-26, B-27, B-30

B-30 (GR)

B-27 (GR)

B-26 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

AB

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-563

STEP 8. Check the right bank injector resistance at 
intermediate connector B-32.
(1) Disconnect the intermediate connector B-32.

(2) Measure the resistance between each male connector side 

terminal.

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

5 at No. 1 cylinder injector.

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

10 at No. 3 cylinder injector.

c. 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 

− 13.5 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.

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:

COMPONENT SIDE

AB

B-32 (B)

1 2 3
6 7 8

4 5
9 10

AK203093

B-32 

INTERMEDIATE

CONNECTOR

AB

AK303055

M

1

2

CONNECTOR: B-01, B-03, B-04

AB

B-01 (GR)

B-03 (GR)

B-04 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB