Fuel Pressure Test
- Release the residual pressure in fuel line. Refer to RELEASE RESIDUAL PRESSURE IN FUEL LINE .CAUTION:
When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the GDS after "Release Residual Pressure in Fuel Line" work.
- Install the Special Service Tool (SST).
- Disconnect the fuel feed tube from the delivery pipe.CAUTION:
There may be some residual pressure even after "Release Residual Pressure in Fuel Line" work, so cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.
- Install the special service tool for measuring the fuel pressure in between the fuel feed tube and the fuel delivery pipe (Refer to the illustration below).
- Disconnect the fuel feed tube from the delivery pipe.
- Inspect fuel leakage on connections among the fuel feed tube, the delivery pipe, and the SST components with IG ON.
- Measure Fuel Pressure.
- Start the engine and measure the fuel pressure at idle.
Fuel Pressure: 338 ~ 348 kPa (3.45 ~ 3.55 kgf/cm, 49.0 ~ 50.5 psi)
NOTE:If the fuel pressure differs from the standard value, repair or replace the related part (Refer to the table below).
TESTING FUEL PRESSURE - ENGINE AT IDLEFuel Pressure Cause Related Part Too Low Fuel filter clogged Fuel Filter Fuel leakage Fuel Pressure Regulator Too High Fuel pressure regulator valve stuck Fuel Pressure Regulator - Stop the engine, and then check for the change in the fuel pressure gauge reading.
Standard Value: The gauge reading should hold for about 5 minutes after the engine stops.
NOTE:If the gauge reading should not be held, repair or replace the related part (Refer to the table below).
TESTING FUEL PRESSURE - ENGINE STOPPEDFuel Pressure
(After Engine Stops)Cause Related Part Fuel Pressure Drops Slowly Leakage on injector Injector Fuel Pressure Drops Immediately Check valve of fuel pump open stuck Fuel Pump - Turn the ignition switch OFF.
- Start the engine and measure the fuel pressure at idle.
- Release the residual pressure in fuel line. Refer to RELEASE RESIDUAL PRESSURE IN FUEL LINE .CAUTION:
When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the GDS after "Release Residual Pressure in Fuel Line" work.
- Test End.
- Remove the Special Service Tool (SST) from the fuel feed tube ant the delivery pipe.
- Connect the fuel feed tube and the delivery pipe.