Fuel Pressure Test

(Refer to RELEASE RESIDUAL PRESSURE IN FUEL LINE .

1. Disconnect the fuel feed tube from the high pressure fuel pump.
   CAUTION: There may be some residual high pressure even after "Release Residual Pressure in Fuel Line" work, so must cover the high pressure line connection part with a shop towel or a cloth to prevent residual fuel from spilling out before removing any high pressure fuel part. Then release pressure by carefully removing connection part. If not, it may result in the injury by high temperature and pressure fuel.
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 figure below).
   Fig 1: Measuring Fuel Pressure Between Fuel Feed Tube And High Pressure Fuel Pump

   Courtesy of HYUNDAI MOTOR AMERICA

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

   Fuel Pressure: 

   343.2 ~ 598.2 kPa (3.5 ~ 6.1 kgf/cm² , 49.8 ~ 86.8 psi)

   NOTE: If the fuel pressure differs from the standard value, repair or replace the related part.
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 "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.