Fuel Pressure: Inspection

WARNING: This page is about a different variant/trim than selected.

WARNING: Before removing the fuel pressure gauge, release fuel pressure.

NOTE: When the fuel pressure is out of specification, check or replace the pressure regulator and pressure regulator vacuum hose.

Release the fuel pressure.
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Open the fuel filler flap lid, and remove the fuel filler cap.
Disconnect the fuel delivery hose, and connect a fuel pressure gauge.

Fig 1: Connecting Fuel Pressure Gauge
Courtesy of SUBARU OF AMERICA, INC.
Install the fuse of fuel pump to main fuse box.
Start the engine.
Measure the fuel pressure while disconnecting pressure regulator vacuum hose from intake manifold.
Fuel pressure:

Standard: 284 - 314 kPa (2.9 - 3.2 kg/cm ² , 41 - 46psi)
After connecting the pressure regulator vacuum hose, measure the fuel pressure.

Fuel pressure:

Standard: 206 - 235 kPa (2.1 - 2.4 kg/cm ² , 30 - 34 psi)

NOTE: The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kg/cm² , 1 to 3 psi) higher than standard values during high-altitude operations.