Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 460

Injector intermediate
harness
Symptom
Fuel pressure too low
Fuel pressure drops after racing
Fuel pressure too high
GDI –
On-vehicle Service
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.
1. Connect the MUT-II to the diagnosis connector.
2. Disconnect the injector intermediate harness connector.
3. Turn the ignition switch to ON.
4. Select "Item No.74" from the MUT-II Data list.
5. 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.
6. Check if the fuel pressure is more than 1 MPa immediately
after 20 seconds have passed since cranking was finished.
7. 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.
Caution
If the fuel pressure drops by more 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.
8. Turn the ignition switch to OFF.
9. 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 – 7 MPa
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.
Probable cause
Fuel leaking to return side due to poor
fuel pressure regulator (high pres-
sure) valve seating or settled spring
Low fuel pump (high pressure)
delivery pressure
Binding valve in fuel pressure regula-
tor (high pressure)
Clogged fuel return hose or pipe
14. Stop the engine and turn the ignition switch to OFF.
15. Disconnect the MUT-II.
13A-101
Remedy
Replace fuel pressure regulator
(high pressure)
Replace the fuel pump
(high pressure)
Replace fuel pressure regulator
(high pressure)
Clean or replace hose or pipe