Check Fuel Pressure

WARNING: This page is about a different car, the 2021 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: 1. Be cautious fuel is explosive and an empty fuel tank can still contain explosive gases. When working on fuel systems make sure to supply adequate ventilation to the work area. Do not smoke, and keep sparks and open flames away.
2. The fuel system remains under pressure when the engine is not running. Release fuel system pressure before disconnecting any fuel line to reduce the chance of personal injury or fire damage to vehicle components.

Turn the ignition switch "OFF". Disconnect Fuel Pump Relay in Junction Box.
Start the engine and wait until it stalls.
Turn the ignition switch "OFF". Connect Fuel Pump Relay.
Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor. (Refer to FUEL PRESSURE TEST )
Activate the fuel pump, check that there are no fuel leaks from the pressure gauge or fuel system.
Measure the fuel pressure at idle.
Specification: 350~600kPa

Is the measured fuel pressure within specifications?

YES

Go to CHECK FUEL INJECTOR LEAKAGE as follows.

Repair or replace according to the table below. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Condition	Possible Cause
Fuel Pressure is too low	Fuel filter, fuel pressure regulator, in-tank fuel hose or the fuel pump
Fuel Pressure is too high	Fuel pressure regulator, hose or pipe