Fuel Pressure Test

(Refer to Fuel Delivery System - "Release Residual Pressure in Fuel Line ")

1. 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.
2. 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).

Fig 1: Installing Special Service Tool

Courtesy of HYUNDAI MOTOR AMERICA

1. 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

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

   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

3. Turn the ignition switch OFF.

(Refer to Fuel Delivery System - "Release Residual Pressure in Fuel Line ")

1. Remove the Special Service Tool (SST) from the fuel feed tube and the high pressure fuel pump.
2. Connect the fuel feed tube and the high pressure fuel pump.