SsangYong Stavic / SsangYong Rodius (2005 year). Manual - part 129

DI07-7

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EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.9

Composition of Fuel System

Components in fuel system are designed to generate and distribute high pressure, and they are controlled electronically
by engine ECU. Accordingly, fuel system is completely different from injection pump type fuel supply system on the
conventional Diesel engine. The fuel injection system in common rail engine is composed of transfer pressure section
that transfers fuel in low pressure, high pressure section that transfers fuel in high pressure and ECU control section.

Fuel route

High pressure pipe

Common rail

Fuel pressure sensor

Fuel filter

Priming pump

Fuel pump

(High pressure pump, transfer pump)

Injector

<Fuel line system>

Fuel tank

Priming pump

Fuel filter

Transfer

pump

Injector

Common rail

High pressure

pump

Fuel pressure

regulation valve

Transfer pressure line

High pressure line

DI07-8

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.9

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

Transfer pres-

sure 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

below - 0.3 bar

below 2 bar

Up to

1050 bar

- 0.6 ~ 0.1 bar

0.05 ~ 0.1 bar

* At IMV full open

DI07-9

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

FUEL SYSTEM

DI ENG SM - 2004.9

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

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 - 2004.9

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.

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.