Mitsubishi 1992 3000GT, Service Manual

Page: 285 / 1308

MULTIPORT
On-Vehicle Inspection of MFI
FUEL INJECTION
(9) Disconnect the vacuum hose from the fuel pressure regu-
lator, and then measure the fuel pressure while using
a finger to plug the end of the hose.
Standard value:
(47-50 psi) at-curb idle
<Turbo> 295-315 (43-45 psi) at curb idle
to be sure that the fuel pressure during idling does
not decrease even after the engine is raced a few times.
(ll)Use a finger to gently press the fuel return hose while
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.
the fuel pressure measured in steps (8) to (11) deviates
from the standard value range, check for the probable
cause by referring to the table below, and then make
the appropriate repair.
Condition
l
Fuel pressure is too low.
l
Fuel pressure drops during
o return side caused by spring
Fuel pressure is too high.
No change of the fuel pres
when the vacuum hose is con-
nected and when not connected.
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