Mitsubishi 3000GT Service Manual page 285

Condition
Fuel pressure is too low.
l
Fuel pressure drops during rac-
l
Fuel pressure is too high.
No change of the fuel pres
when the vacuum hose is con-
nected and when not connected.
MULTIPORT On-Vehicle Inspection of MFI
FUEL INJECTION - ComPonents
(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:
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.
from the standard value range, check for the probable
cause by referring to the table below, and then make
the appropriate repair.
o return side caused by spring deteri-
TSB Revision
<Turbo> 295-315 kPa (43-45 psi) at curb idle