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Fuel filter assembly
Follow the job procedures. If you find a defective component, replace it with new one. 5.
Once disconnected, the fuel pipes between HP pump and fuel rail and between fuel rail and each
injector should be replaced with new ones. The pipes should be tightened tospecified tightening torques
during installation. Over or under torques out of specified range may cause damages and leaks at
connections. Once installed, the pipes have been deformed according to the force during installation,
therefore they are not reusable. The copper washer on injector should be replaced with new one. The
injector holder bolt should be tightened to specified tightening torque as well. If not, the injection point
may be deviated from correct position, and it may cause engine disorder.
Plug the removed components with clean and undamaged sealing caps and store it into the box to
keep the conditions when it was installed. 6.
To supply the fuel to transfer line of HP pump
press the priming pump until it becomes
hard. 7.
Priming pump
Priming pump cap
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Check the installed components again and connect the negative battery cable. Start the engine and
check the operating status.
With Scan Tool, check if there are current faults and erase the history faults. 8.
9.
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2) Diagnostic Test for Engine Fuel System
(1) Overview
If a DTC is displayed on the diagnostic device, check the low pressure- and high pressure fuel systems
before removing the components.
To run the system properly, the electric system must be intact but for the DI engine, the fuel pressure
should be measured also when there is a malfunction even after the diagnostic test with a diagnostic
device.
(2) Hydraulic system
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3) Pressure Test for Fuel System in DI Engine
(1) Test device (Tool kit)
Tool kit for high pressure line
Tool kit for low pressure line
(2) Pre-inspection
Connections in fuel supply line
Fuel level in fuel tank
Air in fuel supply line (air bubbles in fuel supply line or fuel)
Fuel leaks from fuel supply line (low/high pressure line)
Used the specified
Fuel filter contamination -
-
-
-
-
-
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(5) High Pressure System Pressure Test
Fuel rail pressure test
Disconnect the fuel rail pressure sensor
connector and then IMV connector. 1.
Connect the pressure tester to the fuel rail
pressure sensor connector. 2.
Crank the engine 2 times for 5 seconds. 3.
Read the highest pressure value displayed
on the tester display.
If the highest pressure value is 1,050 bar or
less, refer to the section "Fuel System
Check Process". -
-
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How To Use Pressure Tester
Press the "TEST" button on the tester to
check if the message "TEST?" is displayed.
If the button is pressed again at 4 seconds
after starting engine cranking, the highest
pressure is displayed on the tester. 1.
2.
The fuel rail pressure value can be checked using a diagnostic device.
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(6) Low Pressure System Pressure Test
Inspection procedure
All wirings/connectors and fuel lines should be
connected and the engine should work
properly.
Prepare a special tool for low pressure test
and clean it thoroughly to prevent foreign
materials from entering. 1.
2.
Disconnect the key connector for fuel filter connection, and connect both connectors to the fuel filter
and hose. 3.
Start the engine and check visually for clogged low pressure fuel system, excessive air or air entry.
If the fuel flow is not sufficient or air is in the fuel, repair the leak area. 4.
5.
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Static test for backleak of injector
Disconnect the injector return hose and cover
the openings with caps shaped screw (included
in the special tool). 1.
Connect the hose of the container for
measuring backleak to the return nipple of the
injector.
(prevent air entry to the low pressure line) 2.
Disconnect the IMV connector of the high
pressure pump and then fuel pressure
sensor connector. 3.
The connector of the injector can be easily
contaminated. Always keep it clean.
Crank the engine for 5 seconds.
Check the flow volume of injector backleak. 4.
5.
If the value is out of the specified range,
replace the injector.
Flow volume of injector
backleakbelow 20 cm