SsangYong Rexton. Manual - part 73

DI07-8

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.4

Y220_07009

Hydraulic cycle in Fuel Line (Transfer and High Pressure Line)

Transfer pressure

regulation

Pressure limiter

(High pressure)

High pressure pump

Transfer pump

Return

valve

Inlet
valve

Venturi

Fuel filter

Priming pump

Fuel tank

Injector

Common rail

High pressure supply line

Transfer pressure supply line

Return line

over - 0.48 bar

below 2 bar

Up to

1600 bar

DI07-9

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.4

Y220_07012

Components of Low Pressure Transfer Line

Low pressure stage is to supply sufficient fuel to high pressure section and components are as below.

• Fuel tank (including strainer)

• Hand priming pump

• Fuel  filter

• Transfer pump

• Other low pressure fuel hoses

Y220_07010

Y220_07011

Fuel tank

Fuel tank is made of anti-corrosion material and its allowable
pressure is 2 times of operating pressure (more than 0.3 bar).
It has protective cap and safety valve to prevent excessive
pressure building. Also, it has structure to prevent fuel from
leaking in shocks, slopes and corners and to supply fuel
smoothly.

Priming pump

If fuel runs out during driving or air gets into fuel line after fuel
filter replacement, it may cause poor engine starting or dam-
age to each component. Therefore, the hand priming pump is
installed to bleed air from transfer line.

When the vehicle is under the conditions as below, press the
priming pump until it becomes rigid before starting the engine.

- After run out of fuel

- After draining the water from fuel filter
- After replacing the fuel filter

Press the priming pump until it becomes rigid before starting
the engine.

Fuel filter

It requires more purified fuel supply than conventional diesel
engine. If there are foreign materials in the fuel, fuel system
including pump components, delivery valve and injector nozzles
may be damaged.

Fuel filter purifies fuel before it reaches to high pressure pump
to help proper operations in high pressure pump. And more, it
separates water from fuel to prevent water from getting into
FIE system (high pressure line).

DI07-10

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.4

Components of High Pressure Transfer Line

In the high pressure section, sufficient fuel pressure that injectors requires will be generated and stored. The compo-
nents are as below:

• High pressure pump

• Rail pressure sensor

• Pressure limit valve

• Common rail

• High pressure pipe

• Injector

• Fuel pressure regulating valve (IMV)

High pressure pump (including IMV and limit valve)

This is plunger pump that generates high pressure; and driven
by crankshaft with timing chain. The high pressure pump in-
creases system pressure of fuel to approx. 1,600 bar and this
compressed fuel is transferred to high pressure accumulator
(common rail) in tube through high pressure line.

Common rail (including pressure sensor)

It stores fuel transferred from high pressure pump and also
stores actual high pressure of fuel. Even though the injectors
inject fuel from the rail, the fuel pressure in the rail is main-
tained to a specific value. It is because the effect of accumu-
lator is increased by unique elasticity of fuel. Fuel pressure is
measured by rail pressure sensor. And the inlet metering valve
(IMV) included in high pressure pump housing keeps pres-
sure to a desired level.

Y220_07015

Y220_07014

Y220_07013

High pressure pipe (fuel pipe)

Fuel line transfers high pressure fuel. Accordingly, it is made
of steel to endure intermittent high frequency pressure changes
that occur under maximum system pressure and injection
stops. Injection lines between rail and injectors are all in the
same length; it means the lengths between the rail and each
injector are the same and the differences in length are com-
pensated by each bending.

No.1 and 3 cylinder

No. 5 cylinder

No.2 and 4 cylinder

DI07-11

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.4

Fuel Filter Replacement

* Fuel filter change interval: every 30,000 km

* Water separation interval: every 15,000 km max. (same with engine oil change interval)

* Never reuse the removed fuel filter

Y220_07016

Y220_07017

Injectors

The fuel injection device is composed of electrical solenoid
valve, needle and nozzle and controlled by engine ECU. The
injector nozzle opens when solenoid valve is activated to di-
rectly inject the fuel into combustion chamber in engine. When
injector nozzle is open, remaining fuel after injection returns
to fuel tank through return line.

Transfer pump

The transfer pump is included in the housing of the high pres-
sure pump. The transfer pump is the volumetric blade type
pump. To deliver the continuously required fuel volume, the
pump transfers fuel from the fuel tank to high pressure pump.