2008 SSANGYONG KYRON engine

ENGINE FUEL SYSTEM
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1881-01ENGINE FUEL SYSTEM
GENERAL
1. CAUTIONS FOR DI ENGINE
This chapter describes the cautions for DI engine equipped vehicle. This includes the water
separation from engine, warning lights, symptoms when engine malfunctioning, causes and
actions.
1) DI Engine
Comparatively conventional diesel engines, DI engine controls the fuel injection and timing
electrically, delivers high power and reduces less emission.
2) System Safety Mode
When a severe failure has been occurred in a vehicle, the system safety mode is activated to
protect the system. It reduces the driving force, restricts the engine speed (rpm) and stops
engine operation. Refer to "Diagnosis" section in this manual.
3) Water Separator Warning Light
When the water level inside water separator
in fuel filter exceeds a certain level (approx.
39 cc), this warning light comes on and
buzzer sounds.
Also, the driving force of the vehicle
decreases (torque reduction). If these
conditions occur, immediately drain the
water from fuel filter.
For the draining procedures, please refer to
"How to drain the water from fuel filter"
section.
4) Priming Pump
The priming pump installed in fuel pump is the device to fill the fuel into the fuel filter. When the
vehicle is under the conditions as below, press the priming pump until it becomes rigid before
starting the engine.
5) Conditions for Using Priming Pump
After run out of fuel
After draining the water from fuel separator
After replacing the fuel filter -
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ENGINE FUEL SYSTEM
Fuel Filter and Water Separator
1. Fuel filter
2. Water drain plug(water separating operation:every 10,000km)
3. Priming pump
When replaced the fuel filter or drained the water from fuel filter, press the priming pump
until it becomes rigid before starting the engine.
The water drain from fuel filter should be performed whenever changing the engine oil. -
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ENGINE FUEL SYSTEM
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1881-01
6) Draining the Water From Fuel Filter
Place the water container under the fuel
filter. 1.
Turn the drain plug (2) to "A" direction to
drain the water. 2.
Wait until a certain amount of fuel gets
out from the port, then turn the drain plug
to "B" direction to tighten it. 3.
Be careful not to be injured by
surrounding equipment during the
working procedures. -
Press the priming pump until it becomes
rigid. 4.
Start the engine and check the conditions. 5.
If the priming pump is not properly
operated, air may get into the fuel line. It
may cause starting problem or fuel
system problem. Make sure to perform
the job in step 4. -

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ENGINE FUEL SYSTEM
OVERVIEW AND OPERATION PROCESS
1. ELECTRONIC CONTROL OF FUEL SYSTEM
According to input signals from various sensors, engine ECU calculates driver's demand
(position of the accelerator pedal) and then controls overall operating performance of engine
and vehicle on that time.
ECU receives signals from sensors via data line and then performs effective engine air-fuel
ratio controls based on those signals. Engine speed is measured by crankshaft speed (position)
sensor and camshaft speed (position) sensor determines injection order and ECU detects
driver's pedal position (driver's demand) through electrical signal that is generated by variable
resistance changes in accelerator pedal sensor. Air flow (hot film) sensor detects intake ai
r
volume and sends the signals to ECU. Especially, the engine ECU controls the air-fuel ratio by
recognizing instant air volume changes from air flow sensor to decrease the emissions (EGR
valve control). Furthermore, ECU uses signals from coolant temperature sensor and ai
r
temperature sensor, booster pressure sensor and atmospheric pressure sensor as
compensation signal to respond to injection starting, pilot injection set values, various
operations and variables.Components
High pressure fuel pump
Fuel injectors -
-Fuel rail
Electronic control unit(ECU) -
-Fuel pressure sensor
Various sensors and actuators -
-Supply line
Return line
ECU connecting line

ENGINE FUEL SYSTEM
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Fuel Line System
Fuel route
2. 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.
High pressure pipe
Common rail
Fuel pressure
sensor
Priming pump
Fuel pump
(High pressure pump, transfer pump)
Fuel filter
Injector
D20DT: 4 EA
D27DT: 5 EA
common rail

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ENGINE FUEL SYSTEM
3. HYDRAULIC CYCLE IN FUEL LINE
(TRANSFER AND HIGH PRESSURE LINE)
High pressure supply line
Transfer pressure supply
line Return line

ENGINE FUEL SYSTEM
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1881-01
4. 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 -
-
-
-
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1) Fuel Tank
Fuel tank is made of anti-corrosion material
and its allowable pressure is 2 times o
f
operating pressure (more than min. 0.3 bar).
It has protective cap and safety valve to
prevent excessive pressure building. Also, to
supply fuel smoothly, it has structure to
prevent fuel from leaking in shocks, slopes
and corners and.
If fuel runs out during driving or air gets into
fuel line after fuel filter replacement, it may
cause poor engine starting or damage 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.
2) Priming Pump
After run out of fuel
After draining the water from fuel separator
After replacing the fuel filter -
-
-
Press the priming pump until it becomes
rigid before starting the engine.

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ENGINE FUEL SYSTEM
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 prope
r
operations in high pressure pump.
And more, it separates water from fuel to
prevent water from getting into FIE system
(high pressure line).
3) Fuel Filter