Mitsubishi Colt Ralliart. Manual - part 100

 

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Mitsubishi Colt Ralliart. Manual - part 100

 

 

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-354

Examples of Abnormal Wave Patterns

Example 1

Cause of problem
Sensor interface malfunction. (Motor is not oper-

ating)

Wave pattern characteristics
Induced electromotive force from the motor turn-

ing dose not appear.

Example 2

Cause of problem
Open circuit in the line between the EGR valve 

and the engine-CVT-ECU.

Wave pattern characteristics
Current is not supplied to the motor coil on the 

open circuit side. (Voltage dose not drop to 0 
V.)

Furthermore, the induced electromotive force 

waveform at the normal side is slightly differ-
ent from the normal waveform.

AKX01608AE

AKX01609AF

Open
circuit
side

Normal
side

Main

Index

Group

TOC

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-355

ON-VEHICLE SERVICE

THROTTLE BODY (THROTTLE VALVE 
AREA) CLEANING

M1131001001078

CAUTION

When throttle body is cleaned, use the M.U.T.-III 
to initialize the learning value  (Refer to GROUP 
00, Precautions Before Service 

 Initialization 

Procedure for Learning Value in MPI Engine 

P.00-20

).

1. Remove the air intake hose from the throttle body 

assembly.

2. Remove the throttle body assembly.

CAUTION

• Do not spray the cleaning fluid directly to the 

throttle valve.

• Make sure the cleaning fluid does not enter 

the motor from the bypass line. Also make 
sure it does not enter the sensor through the 
shaft.

3. Spray cleaning fluid on a clean cloth.
4. Wipe off the dirt around the throttle valve with the 

cloth sprayed with cleaning fluid.

5. Install the throttle body assembly.
6. Attach the air intake hose.

FUEL PRESSURE TEST

M1131001901509

1. Release residual pressure from the fuel pipe line 

to prevent fuel gush out (Refer to 

P.13A-357

).

CAUTION

Cover the hose connection with rags to prevent 
splash of fuel that could be caused by some 
residual pressure in the fuel pipe line.

2. Disconnect the high-pressure fuel hose at the 

delivery pipe side.

3. Assemble the special tool Injector test set 

(MB992076 or MD998706) of special tool as 
shown in figure.

a. Remove either the instillation adopter for the 

injector or another adopter.

b. Install the special tool quick connector 

(MB991990) and the special tool hose adapter 
(MB992001) to the hose without the adopter.

4. Assemble the fuel pressure measurement tools 

as follows.

<When using the fuel pressure gauge set (special 

tool) >

a. Via a gasket, install the special tool fuel pressure 

gauge set (MB991637 or MB991981) into the 
special tool that has already assembled as 
described.

AK402183AC

AK305751AF

MB992076
or
MD998706

MB992001

MB991990

AK305752AF

MB991637

Gasket

MB992076
or
MD998706

Delivery pipe

High-pressure
fuel hose

AK305604

Delivery pipe

High-pressure
fuel hose

MB991981

AG

Gasket

MB992076
or
MD998706

Main

Index

Group

TOC

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-356

<When using the fuel pressure gauge>

a. Via a suitable O-ring or gasket, install the fuel 

pressure gauge to the special tool that has 
already assembled as described.

5. Install the assembled fuel pressure measurement 

tools between the fuel rail and fuel high-pressure 
hose.

CAUTION

To prevent damage to the M.U.T.-III, always turn 
the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting the M.U.T.-III.
6. Connect the M.U.T.-III to the diagnosis connector.

7. Turn the ignition switch to "ON" position (But do 

not start the engine).

8. Select "Item No. 05" from the M.U.T.-III Actuator 

test to drive the fuel pump. Check that there are 
no fuel leaks from any parts.

9. Finish the actuator test or turn the ignition switch 

to "LOCK" (OFF) position.

10.Start the engine and run at idle.
11.Measure fuel pressure while the engine is running 

at idle.

Standard value: Approximately 324 kPa at 
curb idle

12.Check to see that fuel pressure at idle does not 

drop even after the engine has been raced 
several times.

13.If any of fuel pressure measured in steps 10 to 11 

is out of specification, troubleshoot and repair 
according to the table below.

14.Stop the engine and check change of fuel 

pressure gauge reading. Normal if the reading 
does not drop within 2 minutes. If it does, observe 
the rate of drop and troubleshoot and repair 
according to the table below.

15.Release residual pressure from the fuel pipe line 

(Refer to 

P.13A-357

).

CAUTION

Cover the hose connection with rags to prevent 
splash of fuel that could be caused by some 
residual pressure in the fuel pipe line.
16.Remove the fuel pressure gauge and special tool 

from the delivery pipe.

AK305753

O-ring or gasket

MB992076 or
MD998706

Delivery pipe

High-pressure
fuel hose

Fuel pressure 
gauge set

AG

Symptom

Probable cause

Remedy

• Fuel pressure too low

• Fuel pressure drops after racing

Clogged fuel filter

Replace fuel filter

Fuel leaking to return side due to 
poor fuel regulator valve seating or 
settled spring

Replace fuel pressure regulator

Low fuel pump delivery pressure

Replace fuel pump

Fuel pressure too high

Binding valve in fuel pressure 
regulator

Replace fuel pressure regulator

Symptom

Probable cause

Remedy

Fuel pressure drops gradually after 
engine is stopped

Leaky injector

Replace injector

Leaky fuel regulator valve seat

Replace fuel pressure regulator

Fuel pressure drops sharply 
immediately after engine is 
stopped

Check valve in fuel pump is held 
open

Replace fuel pump

Main

Index

Group

TOC

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-357

17.Fit the fuel high pressure hose over the delivery 

pipe and tighten.

18.Check for any fuel leaks by following the 

procedure in step 7.

19.Disconnect the M.U.T.-III.

FUEL PUMP CONNECTOR 
DISCONNECTION (HOW TO REDUCE 
PRESSURIZED FUEL LINES)

M1131000900837

WARNING

When removing the fuel pipe, etc., release 
fuel pressure to prevent fuel spray.

1. Lift up the rear seat assembly.

CAUTION

Moulding type of floor carpet is used. Be careful 
not to change the shape of carpet when turning it 
over for operation.
2. Remove the rear scuff plate, and turn over the 

floor carpet. (Refer to GROUP 52A, Interior Trims 

P.52A-11

).

3. Remove the service hole cover.

4. Disconnect the fuel tank pump and gauge 

assembly connector.

5. Crank the engine for at least two seconds.

6. If the engine is not started, turn the ignition switch 

to the "LOCK" (OFF) position.

7. If the engine is started, turn the ignition switch to 

the "LOCK" (OFF) position after the engine 
stopped.

8. Connect the fuel tank pump and gauge assembly 

connector.

9. Install the service hole cover.
10.Return the floor carpet to the original state, and 

install the rear scuff plate. (Refer to GROUP 52A, 
Interior Trims 

P.52A-11

).

11.Return the rear seat assembly to the original 

state.

FUEL TANK PUMP OPERATION CHECK

M1131002001491

1. Remove the fuel tank cap.

NOTE: As the fuel tank pump is an in-tank type, 
the fuel tank pump sound is hard to hear. Then 
check the sound from the tank inlet.

2. Check the operating of the fuel tank pump by 

M.U.T.-III to force-drive the fuel tank pump.

3. Install the fuel tank cap.
4. If the fuel tank pump will not operate, check by 

using the following procedure. If normal, check 
the fuel tank pump drive circuit.
(1) Turn the ignition switch to the "LOCK" (OFF) 

position.

(2) Lift up the rear seat assembly.

CAUTION

Moulding type of floor carpet is used. Be careful 
not to change the shape of carpet when turning it 
over for operation.

(3) Remove the rear scuff plate, and turn over the 

floor carpet. (Refer to GROUP 52A, Interior 
Trims 

P.52A-11

).

AC207365AD

Service hole cover

AC400103AB

Fuel tank pump and
gauge assembly connector

AC207379AD

Fuel tank cap

Main

Index

Group

TOC

 

 

 

 

 

 

 

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