Hyundai Tucson (NX4) 2022-2025 Service Manual / Engine Control / Fuel System / Fuel Delivery System / Fuel Pressure Test

Hyundai Tucson: Fuel Delivery System / Fuel Pressure Test

- Fuel Pressure Test

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

• When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the diagnostic tool after "Release Residual Pressure in Fuel Line" work.

2.Install the Special Service Tool (SST).

(1)Disconnect the fuel feed tube from the delivery pipe.

• 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.

(2)Install the special service tool for measuring the fuel pressure in between the fuel feed tube and the fuel delivery pipe (Refer to the figure below).

3.Inspect fuel leakage on connections among the fuel feed tube, the delivery pipe, and the SST components with IG ON.

4. Measure Fuel Pressure

(1)Start the engine and measure the fuel pressure at idle.

Fuel Pressure : 480 - 520 kPa (4.9 - 5.3 kgf/cm, 69.6 - 75.4 psi)

• 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
Too Low	Fuel leakage	Fuel Pressure Regulator
Too High	Fuel pressure regulator valve stuck	Fuel Pressure Regulator

(2)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

• 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 open stuck	Fuel Pump

(3)Turn the ignition switch OFF.

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

• When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the diagnostic tool after "Release Residual Pressure in Fuel Line" work.

6.Test End

(1)Remove the Special Service Tool (SST) from the fuel feed tube ant the delivery pipe.

(2)Connect the fuel feed tube and the delivery pipe.

Components and Components Location

- Component Location [Fuel Tank] 1. Fuel tank2. Canister3. Vapor hose4. Canister Close Valve (CCV)5. Vent hose6. Fuel filler hose7. Fuel tank air filter8. Fuel Tank Pressure Sensor (FTPS)9. Fue ...

Release Residual Pressure in Fuel Line

- Release Residual Pressure in Fuel Line • There may be some residual pressure even after "Release Residual Pressure in Fuel Line" work, so cover the hose connection with a ...

Other information:

Hyundai Tucson (NX4) 2022-2025 Service Manual: Purge Control Solenoid Valve (PCSV)
- Description Purge Control Solenoid Valve (PCSV) is a solenoid valve and is installed on the surge tank and controls the passage between the canister and the intake manifold.The evaporative gases gathered in the canister are delivered to the intake manifold when the PCSV is open by ECM c ...

Hyundai Tucson (NX4) 2022-2025 Service Manual: Balance Shaft Module
- Removal and installation • Be careful not to damage the parts located under the vehicle (floor under cover, fuel filter, fuel tank and canister) when raising the vehicle using the lift.(Refer to General Information - "Lift and Support Points") 1.Remove the oil pan. ...