Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Pressure Test
- Release the residual pressure in fuel line.
(Refer to Fuel Delivery System - "RELEASE RESIDUAL PRESSURE IN FUEL LINE ")
CAUTION: When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work. - Install the Special Service Tool (SST).
- Disconnect the fuel feed tube from the high pressure fuel pump.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 high pressure fuel pump (Refer to the Fig 1 below).
- Disconnect the fuel feed tube from the high pressure fuel pump.
- Inspect fuel leakage on connections among the fuel feed tube, the high pressure fuel pump, and the SST components with IG ON.
- Measure Fuel Pressure.
- Start the engine and measure the fuel pressure at idle.
Fuel Pressure:
480 ~ 520 kPa (4.9 ~ 5.3 kgf/cm2 , 69.6 ~ 75.4 psi)
NOTE: If the fuel pressure differs from the standard value, repair or replace the related part (Refer to the table below).Fuel Pressure Cause Related Part Too Low Fuel filter clogged Fuel Filter Fuel leakage Fuel Pressure Regulator Too High Fuel pressure regulator 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).Fuel Pressure (After Engine Stops) Cause Related Part Fuel Pressure Drops Slowly Leakage on injector Injector Fuel Pressure Drops Immediately Check valve of fuel pump stuck open 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 Fuel Delivery System - "RELEASE RESIDUAL PRESSURE IN FUEL LINE ")
CAUTION: When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work. - Test End
- Remove the Special Service Tool (SST) from the fuel feed tube and the high pressure fuel pump.
- Connect the fuel feed tube and the high pressure fuel pump.
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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.
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