Checking Fuel Pressure

1992 Infiniti M30 2D ConvertibleSECTION Checking Fuel Pressure
  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 indication of 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

Application psi (kg/cm2 ) (1) psi (kg/cm2 ) (2)
G20 36 (2.5) 43 (3.0)
M30 & 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.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.