Mitsubishi 1989-1993 GALANT Service Manual page 455

FUEL SYSTEM <DOHC> -
Condition
. Fuel pressure is too low.
. Fuel pressure drops during racing.
. No fuel pressure in fuel return hose.
Fuel pressure is too high.
No change of the fuel pressure when
vacuum hose is connected and when not
connected.
I
regulator, and then measure the fuel pressure while using a
finger to plug the end of the hose.
Standard value:
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.
Clogging of the fuel return hose
and/or the pipe.
Damaged vacuum hose or nipple
clogging.
Malfunction of the fuel pressure
control system <Turbo>
TSB Revision
13-313
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.
Checking the fuel pressure control
system <Turbo> I