Mitsubishi 1989-1993 GALANT Service Manual page 246

04
FUEL SYSTEM <SOHC-8 VALVE>
Condition
. Fuel pressure too low.
IS
. Fuel pressure drops during racing.
. No fuel pressure In fuel return hose.
Fuel pressure is too high
No change of the fuel pressure when Damaged vacuum hose or nipple
vacuum hose connected and when not
IS
connected.
Condition
After the engine is stopped, the fuel Injector leakage
pressure drops graudally.
There a sudden sharp drop of the fuel
IS
pressure immediately after the engine is
stopped.
regulator, and then measure the fuel pressure while using a
finger to plug the end of the hose.
Standard value: 330-370 kPa (47-53 psi) at curb idle
not decrease even after the engine is raced a few times.
repeatedly racing the engine, and check to be sure that
there is fuel pressure in the return hose also.
NOTE
There will be no fuel pressure in the return hose if there is
insufficient fuel flow.
from the standard value range, check for the probable
cause by referring to the table below, and then make the
appropriate repair.
Probable cause
Fuel filter is clogged.
Malfunction of the valve seat with-
in the fuel pressure regulator, or
fuel leakage to return side caused
by spring deterioration.
Fuel pump low discharge pressure.
The valve within the fuel pressure
regulator is sticking.
fuel return hose
Clogging of the
clogging.
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.
determine the cause of the problem and make the
appropriate repair.
Probable cause
Leakage at the fuel pressure reg-
ulator valve seat
The check valve (within the fuel Replace the fuel pump.
pump) is not closed.
TSB Revision
speed
Remedy
Replace the fuel filter.
Replace the fuel pressure regula-
tor.
Replace the fuel pump.
Replace the fuel pressure regula-
tor.
Clean or replace the hose and/or
pipe.
Replace the vacuum hose, or clean
the nipple.
Remedy
Replace the injector.
Replace the fuel pressure regula-
tor.