Mitsubishi 380. Manual - part 625

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-592

STEP 3. Check the advance ignition timing.
Ignition timing is controlled by the ENGIN-ECUand will vary
depending on engine requirement..

Q: Is the advance ignition timing normal?

YES : Go to Step 4.
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 4. Using diagnostic tool, check data list.

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing or disconnecting diagnostic tool.
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check the following items in the data list. Refer to Data List

Reference Table

P.13A-637

a. Item 5: Intake Air Temperature Sensor.
b. Item 6: Engine Coolant Temperature Sensor.

c. Item AD: Right Bank Heated Oxygen Sensor (rear).

d. Item AC: Right Bank Heated Oxygen Sensor (front).
e. Item AF: Left Bank Heated Oxygen Sensor (rear).

f. Item AE: Left Bank Heated Oxygen Sensor (front).

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

Q: Are they operating properly?

YES : Go to Step 5.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-593

STEP 5. Using diagnostic tool, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items of data list. Refer to Data List

Reference Table

P.13A-637

a. Item AC: Right Bank Heated Oxygen Sensor (front).
b. Item AE: Left Bank Heated Oxygen Sensor (front).

• Voltage should fluctuate between 0 − 0.4 volt and 0.6 −

1.0 volt while idling after the engine has been warmed.

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

Q: Are they operating properly?

YES : Go to Step 7.
NO : Go to Step 6.

STEP 6. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-661

Q: Is the fuel pressure normal?

YES : Check the following items, and repair or replace the

defective items.

a. Vacuum leak.

• Broken intake manifold gasket.

• Broken air intake hose.

• Broken vacuum hose.

• Positive crankcase ventilation valve does

not operate.

b. Injector clogged.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-594

STEP 7. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-661

Q: Is the fuel pressure normal?

YES : Check the following items, and repair or replace the

defective items.

a. Check the ignition coil and spark plugs.
b. Check compression pressure.

c. Check the fuel filter or fuel line for clogging.

d. Broken air intake hose.
e. Clogged air cleaner.

f. Clogged exhaust system.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

INSPECTION PROCEDURE 19: Surge.

COMMENT

• Defective ignition system, abnormal air/fuel ratio,

the electronic control throttle valve system failed,
etc. are suspected.

TROUBLESHOOTING HINTS (The most
likely causes for this case:)

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the electronic control throttle valve

system.

• Refer to component locations GROUP-

• Refer to configuration diagrams GROUP-

• Refer to circuit diagrams GROUP-

DIAGNOSIS

Required Special Tools:

• Diagnostic tool(MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-595

STEP 1. Using diagnostic tool, read the diagnostic trouble
code (DTC).

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing 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 to the "ON" position.

Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13A-17

NO : Go to Step 2.

STEP 2. Using diagnostic tool, check actuator test items
01, 02, 03, 04, 05, 06: Injector.
(1) Turn the ignition switch to the "ON" position.
(2) Check following items in the actuator test. Refer to Actuator

Test Reference Table

P.13A-644

a. Item 01, 02, 03, 04, 05, 06: Injector.

(3) Turn the ignition switch to the "ON" position.

Q: Are thy operating properly?

YES : Go to Step 3.
NO : Refer to DTC P0201