Fuel Pressure Test: Notes

WARNING: This page is about a different car, the 2014 Hyundai Elantra GT and 2013 Hyundai Elantra GT. However, it is still accessible from the selected car via links, so may be relevant.

Release the residual pressure in fuel line.
(Refer to Fuel Delivery System - "RELEASE RESIDUAL PRESSURE IN FUEL LINE ")
CAUTION:
- When removing the fuel pump fuse, 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).
1. 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.
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).
  
  Fig 1: Measuring Fuel Pressure In Between Fuel Feed Tube And Fuel Delivery Pipe
  Courtesy of HYUNDAI MOTOR AMERICA
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:

355 ~ 365 kPa (3.4 ~ 3.7 kgf/cm² , 48.6 ~ 52.9 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
Too Low	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).

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.

Release the residual pressure in fuel line.
(Refer to Fuel Delivery System - "RELEASE RESIDUAL PRESSURE IN FUEL LINE ")
CAUTION:
- When removing the fuel pump fuse, 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
1. Remove the Special Service Tool (SST) from the fuel feed tube and the delivery pipe.
2. Connect the fuel feed tube and the delivery pipe.