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Home >> Nissan-Datsun >> 1998 >> Sentra Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 15 (Engine Controls - Basic Testing) >> Fuel System >> Fuel Pressure >> Checking Fuel Pressure
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Checking Fuel Pressure

WARNING: This page is about a different car, the 1998 Infiniti Q45 and 1998 Infiniti I30. However, it is still accessible from the selected car via links, so may be relevant.
  1. Disconnect fuel hose on fuel filter outlet side and install fuel pressure gauge. Replace pump fuse. Start engine and check fuel line connections for leakage. Check fuel pressure with engine idling. Record fuel pressure gauge reading.
  2. Disconnect and plug vacuum hose from pressure regulator and immediately note fuel pressure. Record fuel pressure gauge reading. See FUEL PRESSURE  table.
  3. Connect a hand-held vacuum pump to fuel pressure regulator. Start engine and watch fuel pressure gauge as vacuum is changed. Fuel pressure should decrease as vacuum increases. If result is not as specified, replace fuel pressure regulator.
FUEL PRESSURE (At Idle)

Application (1) psi (kg/cm2 ) (2) psi (kg/cm2 )
I30 & Q45 34 (2.4) 43 (3.0)
(1) With vacuum hose connected at fuel pressure regulator.
(2) With vacuum hose disconnected at fuel pressure regulator.