Fuel Pressure Inspection (Low-Pressure System)

Fuel Pressure Inspection (Low-Pressure System)

1. 1
   Release the residual fuel pressure in the fuel line. (Refer to Fuel System - "Release Residual Fuel Pressure in Line")

   When the fuel pump fuse is removed, a diagnostic trouble code (DTC) may be set. After completing the "Fuel Line Residual Pressure Release" procedure, clear the DTC with a diagnostic scan tool.

2. 2
   Install the Special Service Tool (SST).

   1. Disconnect the fuel feed hose from the injection pipe.

      Some residual pressure may remain even after completing "Fuel Line Residual Pressure Release." Therefore, cover the hose connection with a shop towel to prevent fuel spray before disconnecting any fuel connection.

   2. Install the special service tool for measuring fuel pressure between the fuel feed hose and the fuel feed pipe (refer to the illustration below).
      • For 09353-02100

      

      • For 0K353-D4100

      

3. 3
   With the ignition ON, inspect for fuel leaks at the connections between the fuel feed tube, the pipe, and the SST components.
4. 4
   Measure the fuel pressure.

   1. Start the engine and measure the fuel pressure at idle. Fuel pressure: more than 290 kPa (more than 2.9 bar, more than 2.95 kgf/cm², more than 42.06 psi)

      If the fuel pressure does not meet the specification, repair or replace the applicable part. (Refer to the table below.)

      Fuel Pressure	Cause	Related Part
      Too low	Clogged fuel filter	Fuel filter
      	Fuel leakage	Fuel Pressure Regulator
      Too high	Fuel pressure regulator stuck	Fuel Pressure Regulator

   2. Stop the engine, and then check the fuel pressure gauge reading for changes. Specification: the gauge reading should be maintained for approximately 5 minutes after the engine is stopped.

      If the gauge reading does not hold, repair or replace the applicable part. (Refer to the table below.)

      Fuel Pressure (After Engine Stop)	Cause	Related Part
      Fuel pressure drops slowly	Injector leakage	Injector
      Fuel pressure drops immediately	Fuel pump check valve stuck open	Fuel pump

   3. Turn the ignition off.
5. 5
   Release the residual fuel pressure in the fuel line. (Refer to Fuel System - "Release Residual Fuel Pressure in Line")

   When the fuel pump fuse is removed, a diagnostic trouble code (DTC) may be set. After completing the "Fuel Line Residual Pressure Release" procedure, clear the DTC with a diagnostic scan tool.

6. 6
   Complete the test.

   1. Remove the special service tool (SST) from the low-pressure fuel feed tube and the low-pressure inlet of the high-pressure fuel pump.
   2. Connect the low-pressure fuel feed tube and the hose to the low-pressure inlet of the high-pressure fuel pump.