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Mitsubishi Space Star. Manual - part 49

GDI –

On-vehicle Service

13A-123

Connect the MUT-

to the diagnosis connector.

Caution
Turn off the ignition switch before disconnecting or
connecting the MUT-

Turn the ignition switch to ON. (But do not start the engine.)

Select “Item No. 07” from the MUT-

Actuator test to drive

the fuel pump (low pressure) at the fuel tank side. Check
that there are no fuel leaks from any parts.

Finish the actuator test or turn the ignition switch to OFF.

Start the engine and run at idle.

10. Measure fuel pressure while the engine is running at idle.

Standard value: approximately 324 kPa

11. Check to see that fuel pressure at idle does not drop

even after the engine has been raced several times.

12. If fuel pressure is out of the standard value, troubleshoot

and repair according to the table below.

Symptom

Probable cause

Remedy

Fuel pressure too low

Fuel pressure drops after racing

Clogged fuel filter

Replace fuel filter

Fuel pressure drops after racing

Fuel leaking to return side due to poor
fuel pressure regulator (low pressure)
valve seating or settled spring

Replace fuel pressure regulator
(low pressure)

Low fuel pump (low pressure) delivery
pressure

Replace the fuel pump (low pressure)

Fuel pressure too high

Binding valve in fuel pressure regula-
tor (low pressure)

Replace fuel pressure regulator
(low pressure)

Clogged fuel return hose or pipe

Clean or replace hose or pipe

13. 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.

Symptom

Probable cause

Remedy

Fuel pressure drops gradually after
engine is stopped

Leaky fuel pressure regulator (low
pressure) valve seat

Replace fuel pressure regulator
(low pressure)

Fuel pressure drops sharply
immediately after engine is stopped

Check valve in fuel pump (low
pressure) is held open

Replace the fuel pump (low pressure)

14. Release residual pressure from the fuel pipe line.

NOTE
Refer to SPACE STAR ’99 Workshop Manual (Pub. No.
CMXE99E1) GROUP 13A – On-vehicle Service.

GDI –

On-vehicle Service

13A-124

15. Remove the fuel pressure gauge and special tools from the

fuel pump (high pressure).

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. Replace the O-ring at the end of the high-pressure fuel

hose with a new one. Furthermore, apply engine oil to
the new O-ring before replacement.

17. Fit the high-pressure fuel hose to the fuel pump (high

pressure) and tighten the mounting bolt to specified torque.

18. Check for any fuel leaks by following the procedure in

step 7.

19. Disconnect the MUT-

MEASUREMENT OF FUEL HIGH PRESSURE BETWEEN
FUEL PUMP (HIGH PRESSURE) AND INJECTORS

NOTE
Measurement of the fuel pressure between the fuel pump
(high pressure) and the injectors should be carried out after
checking that the fuel pressure between the fuel pump (low
pressure) and the fuel pump (high pressure) is normal.

Connect the MUT-

to the diagnosis connector.

Disconnect the injector intermediate harness connector.

Turn the ignition switch to ON.

Select “Item No. 74” from the MUT-

Data list.

Crank the engine continuously for 2 seconds or more,
and visually check that there are no fuel leaks from any
parts.

Caution
If any fuel leaks appear, stop cranking immediately
and repair the source of the leak.

Check if the fuel pressure is more than 1 MPa immediately
after 20 seconds have passed since cranking was finished.

If the fuel pressure is lower than 1 MPa, it means that
there is likely to be a leak in the high-pressure fuel system,
so this system should be checked.

Turn the ignition switch to OFF.

Connect the injector intermediate harness connector.

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

Standard value: 4 – 6.9 MPa

Injector intermediate harness

GDI –

On-vehicle Service

13A-125

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

after the engine has been raced several times.

13. If fuel pressure is out of the standard value, troubleshoot

and repair according to the table below.

Symptom

Probable cause

Remedy

Fuel pressure too low

Fuel pressure drops after racing

Fuel leaking to return side due to poor
fuel pressure regulator valve seating
or settled spring in the fuel pump (high
pressure).

Replace fuel pump (high pressure)

Low fuel pump (high pressure)
delivery pressure

Replace the fuel pump
(high pressure)

Fuel pressure too high

Clogged fuel pressure regulator valve
in the fuel pump (high pressure)

Replace fuel pump (high pressure)

Clogged fuel return hose or pipe

Clean or replace hose or pipe

14. Stop the engine and turn the ignition switch to OFF.
15. Disconnect the MUT-

FUEL LEAK CHECK

Connect the MUT-

to the diagnosis connector.

Disconnect the injector intermediate harness connector.

Turn the ignition switch to ON.

Select “Item No. 74” from the MUT-

Data list.

Crank the engine continuously for two seconds or more,
and visually check that there are no fuel leaks from any
parts.

Caution
If any fuel leaks appear, stop cranking immediately
and repair the source of the leak.

Crank the engine, and then measure fuel pressure
immediately after 20 seconds.

Limit: Minimum 1 MPa

Caution
If the fuel pressure is less than 1 MPa, there may
be a partial fuel leak in the high-pressure fuel system.

Turn off the ignition switch.

Reconnect the injector intermediate connector.

Remove the MUT-

Injector intermediate harness

GDI –

On-vehicle Service

13A-126

COMPONENT LOCATION

Name

Symbol

Name

Symbol

Engine-A/T-ECU <A/T>

Oxygen sensor (front)

Ignition failure sensor

Oxygen sensor (rear)

Content .. 47 48 49 50 ..