2013 SSANGYONG TURISMO Engine mount

15-12
(2) Fuel injection control
a. Multi injection
Fuel injection process consists of 3 steps: Main Injection, Pilot Injection, Post Injection
This is the injection before main injection. This consists of 1st and 2nd pilot injection, and Pre-injection.
The steps are normally used to control the NOx, noise, idle stability and engine vibration. Inject a small
amount of fuel before main injection prevents the instant high combustion temperature. It reduces the
NOx and decreases the engine noise and vibration. The main injection produces the actual output.
The vehicle output is based on the main injection. The post injection is the injection process after main
injection and consists of ‘After injection”, “Post 1 injection” and “Post 2 injection”. All of post
injections are to reduce the PM and harmful exhaust gas. The post injection does not make the actual
output. The post injection activates the fuel by injecting the fuel to the incompletely combusted gas
after primary combustion. Through the process, the PM and smoke in the exhaust gas could be
reduced. There are totally 7 injections as shown in the figure. However, all of 7 injections are not
performed during driving because it decreases the fuel economy. Totally 5 injections can be performed
in one cycle.
InjectionFunction
MainProduces engine power
Pilot 1Reduces PM by injecting before
main injection.AfterPM control
Pilot 2Reduces NOx and noise by
shortening main injection delay
due to flammability Post 1Reduces PM by enabling fuel
activation.
PreControls NOx emission level,
Combustion noise and
Stable idle Post 2
Activates CDPF by increasing
exhaust gas temperature and
supplying reduction material

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b. Pilot Injection
Injection before main injection. Consists of 1st and 2nd pilot injection, and Pre-injection
Inject a small amount of fuel before main injection to make the combustion smooth. Also, called as
preliminary injection or ignition injection. This helps to reduce Nox, engine noise and vibration, and to
stabilize the idling.
The injected fuel volume is changed and stopped according to the coolant temperature and intake air
volume.
Pilot injection is much earlier than main injection due to higher engine rpm
Too small injection volume (insufficient injection pressure, insufficient fuel injection volume in
main injection, engine braking)
System failure (fuel system, engine control system) -
-
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Pilot injection
Main injection
Combustion pressure with pilot injection
Combustion pressure without pilot injection 1.
2.
1a.
2b. Stop conditions
Combustion pressure characteristic curve for pilot injection ▶

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A fourth correction is made according to the pressure error.
This correction is used to reduce the injection timing advance when the pressure in the rail is higher
than the pressure demand.
A fifth correction is made according to the rate of EGR.
This correction is used to correct the injection timing advance as a function of the rate of exhaust
gas recirculation. -
-
When the EGR rate increases, the injection timing advance must in fact be increased in order to
compensate for the fall in termperature in the cylinder.
A. Main Flow Control
The main flow represents the amount of fuel injected into the cylinder during the main injection. The
pilot flow represents the amount of fuel injected during the pilot injection.
The total fuel injected during 1 cycle (main flow + pilot flow) is determined in the following manner.
When the driver depress the pedal, it is his demand which is taken into account by the system in
order to determine the fuel injected.
When the driver release the pedal, the idle speed controller takes over to determine the minimum
fuel which must be injected into the cylinder to prevent the enigne from stalling. -
-
The driver demand is the translation of the pedal position into the fuel demand. It is calculated as a
function of the pedal position and of the engine speed. The driver demand is filtered in order to limit the
hesitations caused by rapid changes of the pedal position. A mapping determines the maximum fuel
which can be injected as a function of the driver demand and the rail pressure. Since the flow is
proportional to the injection time and to the square root of the injection pressure, it is necessary to limit
the flow according to the pressure in order to avoid extending the injection for too long into the engine
cycle. The system compares the driver demand with this limit and chooses the smaller of the 2 values.
The driver demand is then corrected according to the coolant temperature. This correction is added to
the driver demand.
(5) Fuel Control
B. Driver Demand

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F. Pilot Flow Control
The pilot flow represents the amount of fuel injected into the cylinder during the pilot injection. This
amount is determined according to the engine speed and the total flow.
A first correction is made according to the air and water temperature.
This correction allows the pilot flow to be adapted to the operating temperature of the engine. When
the engine is warm, the ignition time decreases because the end-of-compression temperature is
higher. The pilot flow can therefore be reduced because there is obviously less combustion noise
when the engine is warm.
A second correction is made according to the atmospheric pressure. -
-
During starting, the pilot flow is determined on the basis of the engine speed and the coolant
temperature.
G. Cylinder Balancing Strategy
Balancing of the point to point flows ▶
The pulse of each injector is corrected according to the difference in instantaneous speed measured
between 2 successive injectors.
The instantaneous speeds on two successive injections are first calculated.
The difference between these two instantaneous speeds is then calculated.
Finally, the time to be added to the main injection pulse for the different injectors is determined.
For each injector, this time is calculated according to the initial offset of the injector and the
instantaneous speed difference.
Detection of an injector which has stuck closed ▶
The cylinder balancing strategy also allows the detection of an injector which has stuck closed. The
difference in instantaneous speed between 2 successive injections then exceeds a predefined
threshold. In this case, a fault is signaled by the system.

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C. Learning Conditions
Idle MDP learning Drive MDP learning
Coolant temperatureover 60℃ over 60℃
Vehicle speedIdling over 50km/h (over 5 seconds)
Engine rpm2,000 to 2,500 rpm
Fuel temperature0 < Fuel temperature < 80℃
Learning2 times for each cylinder (every 5
seconds)2 times for each cylinder
(every 5 seconds)
If MDP learning is not properly performed, engine vibration and injection could be occurred.
MDP learning should be performed after replacing ECU, reprogramming and replacing injector. -
-
D. Injector characteristic curve for rail pressure
The fuel injection curve is also called injection characteristic curve as shown above. The amount of
injected fuel is proportional to the square root of injection period and rail pressure.

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Load Engine speedSwirl
valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000 rpm Closed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas))
High speed,
High loadover 3,000 rpm Open LightIncrease charge efficiency, higher
engine power
The variable swirl valve actuator operates when
turning the ignition switch ON/OFF position to
open/close the swirl valve. In this period, the
soot will be removed and the learning for swirl
valve position is performed.
Swirl: This is the twisted (radial) air flow along the cylinder wall during the intake stroke. This
stabilizes the combustion even in lean air-fuel mixture condition.
Swirl valve
E. Features
Swirl and air intake efficiency
To generate the swirl, the intake port should be serpentine design. This makes the resistance in air
flow. The resistance in air flow in engine high speed decreases the intake efficiency. Eventually, the
engine power is also decreased, Thus, the swirl operation is deactivated in high speed range to
increase the intake efficiency.
Relationship between swirl and EGR
To reduce Nox, it is essential to increase EGR ratio. However, if EGR ratio is too high, the PM also
could be very higher. And, the exhaust gas should be evenly mixed with newly aspired air.
Otherwise, PM and CO are dramatically increased in highly concentrated exhaust gas range and
EGR ratio could not be increased beyond a certain limit. If the swirl valve operates in this moment,
the limit of EGR ratio will be higher. -
-
F. Relationship between swirl and fuel injection pressur
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If the
swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when
the swirl is too strong.

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Electric throttle
bodyAccelerator
pedal
moduleD20DTR
ECU
(9) EGR control
A. Overview
The EGR (Electric-Exhaust Gas Recirculation) valve reduces the NOx emission level by recirculating
some of the exhaust gas to the intake system.
To meet Euro-V regulation, the capacity and response rate of E-EGR valve in D20DTR engine have
been greatly improved. The EGR cooler with high capacity reduces the Nox, and the bypass valve
reduces the CO and HC due to EGR gas before warming up.
Also, the engine ECU adjusts the E-EGR opening by using the air mass signal through HFM sensor. If
the exhaust gas gets into the intake manifold when the EGR valve is open, the amount of fresh air
through HFM sensor should be decresed.
B. Components
E-EGR cooler
Coolant
temperature
sensorOxygen sensor
HFM (intake
air
temperature)
Crankshaft
position
sensorE-EGR valve
T-MAP
sensor

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F. Features
As EGR ratio goes up, smoke volume will be
higher. But, this lowers the combustion
chamber temperature and accordingly the
concentration of NOx is decreased. The point
with highest NOx is immediately after TDC.As EGR temperature goes up, the
concentration of NOx will be higher. Thus, it is
necessary to cool down the exhaust gas.
However, during engine cooled, it may cause
large amount of PM. To prevent this, the
exhaust gas is bypassed the EGR cooler.