Mitsubishi Stealth 1994 Import Service Manual page 600

MULTIPORT FUEL INJECTION -
Condition
After the engine is stopped, the
fuel pressure drops gradually.
There is a sudden sharp drop of
the fuel pressure immediately
after the engine is stopped.
On-Vehicle Inspection of MFI Components
indicated by the fuel pressure gauge. The condition is
normal if there is no decrease of the indicated value within
two minutes.
If there is a decrease of the indicated value, monitor the ,
speed of the decrease, and, referring to the table below, d
determine the cause of the problem and make the
appropriate repair.
Probable cause
Injector leakage.
Leakage at the fuel pressure
regulator valve seat.
The check valve (within the fuel
pump) is not closed.
from the delivery pipe.
Caution
Because there will be some residual pressure in the fuel
pipe line, use a shop towel to cover so that fuel doesn't
splatter.
with a new one.
tighten the installation bolt at the specified torque.
Tightening torque: 5.0 Nm (3.6 ft.lbs.)
the fuel pump so as to activate the fuel pump.
line.
Remedy
Replace the injector.
Replace the fuel pressure regulator.
Replace the fuel pump.