Iveco Daily Euro 4. Manual — part 37

Figure 283

HIGH-PRESSURE ELECTRONIC INJECTION SYSTEM COMPONENTS LAYOUT

1. Timing phase sensor - 2. Electric injectors - 3. Preheating plug - 4. Coolant temperature sensor - 5. Electromagnetic fan - 6. E.G.R. valve modulator - 7. Engine revs sensor - 8. Compressor (if any) -

9. High-pressure pump - 10. Connector for fuel temperature sensor, heater and fuel filter clogging sensor (on request) - 11. Pressure regulator - 12. Fuel filter - 13. Fuel tank - 14. Fuel gauge with built-in electric

fuel pump - 15. Control unit with atmospheric pressure sensor - 16. Battery - 17. Accelerator pedal sensor - 18. Clutch pedal sensors - 19. Brake pedal sensors - 20. Low-pressure fuel pipes - 21. Throttle valve

assembly - 22. Hydraulic accumulator (rail) air pressure/temperature sensor - 23. Air pressure/temperature sensor - 24. Hydraulic accumulator - 25. Engine revs counter - 26. Display - 27. Tachograph.

Common Rail MS6.3 is a high-pressure electronic injection
system for fast diesel engines with direct injection.
Its main features comprise:

-

high injection pressures available (1600 bar);

-

these pressures can be modulated between 250 bar up
to the maximum operating pressure of 1600 bar,
irrespective of the speed of rotation and engine load;

-

capacity to operate at very high speeds (up to 6000
rpm);

-

injection control precision (injection duration and
advance);

-

lower consumption;

-

lower emissions.

The main functions of the system are basically as follows:

-

checking fuel temperature;

-

checking engine coolant temperature;

-

checking amount of fuel injected;

-

checking idling speed;

-

cutting off fuel in release phase;

-

checking cylinder balancing when idling;

-

checking anti-sawing;

-

checking smokiness at exhaust on acceleration;

-

checking exhaust gas recirculation (E.G.R.);

-

checking top speed limit;

-

checking glow plugs;

-

checking activation of air-conditioning system (if any);

-

checking auxiliary fuel pump;

-

checking position of cylinders;

-

checking main and pilot injection advance;

-

checking closed cycle of injection pressure;

-

checking turbocharging pressure;

-

self-diagnosis;

-

connection with immobilizer unit;

-

checking maximum torque limitation.

The system makes pre-injection (pilot injection) possible
before the TDC with the advantage of decreasing the
derivative of the pressure in the combustion chamber,
lowering the noise level of combustion, which is typical of
direct injection engines.
The control unit checks the amount of fuel injected,
adjusting the line pressure and injection times.
The information the control unit processes to regulate the
amount of fuel to be injected comprises:

-

engine speed;

-

coolant temperature;

-

turbocharging pressure;

-

air temperature;

-

intake air quantity;

-

battery voltage;

-

diesel pressure;

-

position of throttle pedal.

HIGH-PRESSURE ELECTRONIC
INJECTION SYSTEM (MS 6.3 - EDC 16)
General

high pressure
low pressure

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SYSTEM OPERATION
Self-diagnosis — BLINK CODE

The control unit self-diagnosis system checks the signals from
the sensors, comparing them with the admitted limits (see
relative heading):

Immobilizer recognition

When the control unit receives the signal of the key on ”MAR”
it communicates with the immobilizer control unit to enable
starting.

Checking fuel temperature

With the fuel temperature greater than 75

°C, detected by the

sensor on the fuel filter, the control unit operates the pressure
regulator to decrease the line pressure (injection times are not
changed). If the temperature exceeds 90

°C, the power is

reduced to 60%.

Checking engine coolant temperature

The control unit, depending on the temperature:

-

of the engine coolant, turbocharging air and fuel, operates
the electromagnetic fan (Baruffaldi) and switches on the
coolant temperature warning light.

Checking quantity of fuel injected

According to the signals from the sensors and the mapped
values, the control unit:

-

operates the pressure regulator;

-

varies the ”pilot” injection time to 2200 rpm;

-

varies the ”main” injection time.

Checking idling adjustment

The control unit processes the signals from the various sensors
and regulates the amount of fuel injected:

-

it operates the pressure regulator;

-

it varies the injection times of the electro-injectors.

Within certain thresholds the speed takes account of the
battery voltage.

Fuel cut-off in release phase

In the phase of releasing the throttle pedal the control unit
actuates the following logic elements:

-

it cuts off supply to the electro-injectors;

-

it partially reactivates supply to the electro-injectors
before reaching idling speed;

-

it operates the fuel pressure regulator.

Checking cylinder balancing on idling

According to the signals received from the sensors, the control
unit controls the regularity of the torque at idling speed:

-

it varies the amount of fuel injected into the single
electro-injectors (injection time).

Checking regular engine rotation (anti-sawing)

It ensures regular engine rotation at a constant rate while
increasing revs.
The control unit processes the signals received from the
sensors and determines the amount of fuel to be injected via:

-

the pressure regulator;

-

the electro-injector opening time.

Checking

smokiness

at

exhaust

on

acceleration

With heavy acceleration, on the basis of the signals received
from the air introduction meter and engine speed sensor, the
control unit determines the optimum amount of fuel to inject:

-

it operates the pressure regulator;

-

it varies the electro-injector injection time.

Checking exhaust gas recirculation (E.G.R.)

Depending on the engine load and the signal from the
accelerator pedal sensor, the control unit limits the amount of
air taken in, actuating partial suction of the exhaust gases.

Checking top speed limit

Depending on the number of revs, the control unit actuates
two action strategies:

-

at 4250 rpm it cuts off the fuel, decreasing the
electro-injector opening time;

-

over 5000 rpm it deactivates the electro-injectors.

Checking regular rotation on acceleration

Regular progression is assured in all conditions by the control
of the pressure regulator and the electro-injector opening
time.

Checking glow plug control unit

The injection control unit, in the phase of:

-

starting

-

after-starting

times operation of the glow plugs according to the engine
temperature.

Checking activation of air-conditioning system

The control unit operates the air-conditioning compressor:

-

switching it on/off when the relative switch is pressed;

-

momentarily turning it off (approximately 6 sec.) if the
engine coolant reaches the set temperature.

Checking fuel pump

Irrespective of the speed, the control unit:

-

supplies the auxiliary fuel pump with the key on MAR;

-

cuts off auxiliary pump supply if the engine is not started
up within a few seconds.

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Checking diesel warming

It times operation of diesel warming in relation to ambient
temperature.

Checking cylinder position

During each turn of the engine, the control unit recognizes
which cylinder is in the power stroke and operates the
injection sequence for the appropriate cylinder.

Checking pilot and main injection timing

According to the signals from the various sensors, including the
absolute pressure sensor built into the control unit, the control
unit determines the optimum point of injection according to
internal mapping.

Checking injection pressure closed cycle

Depending on the engine load, determined by processing the
signals from the various sensors, the control unit operates the
regulator to obtain optimum line pressure.

Fuel supply

The fuel supply is calculated in relation to:

-

accelerator pedal position

-

engine speed

-

quantity of air introduced.

The outcome may be corrected in relation to:

-

the water temperature.

Or to avoid:

-

noise

-

smoke

-

overloading

-

overheating

-

turbine over-revving.

The delivery can be modified in the case of:

-

action of external devices (ABS), ABD, EDB

-

serious trouble decreasing the load or stopping the
engine.

After determining the mass of air introduced by measuring its
volume and temperature, the control unit calculates the
corresponding mass of fuel to inject into the relevant cylinder
(mg per delivery) also taking into account the temperature of
the diesel.
The mass of fuel calculated in this way is first converted into
volume (mm

3

per delivery) and then into degrees of throw,

or duration of injection.

Correcting flow rate according to water
temperature

A cold engine meets with greater resistance during operation:
friction is high, the oil is still very viscous, and the various
clearances are not yet optimized.
In addition, the injected fuel tends to condense on the metal
surfaces that are still cold.
The fuel supply for a cold engine is therefore greater than for
a warm one.

Correcting flow rate to avoid noise, smoke or
overloading

The behaviour that could lead to this kind of trouble is well
known.

The designer has therefore included special instructions in the
control unit to avoid it.

De-rating

In the event of the engine overheating, injection is modified,
decreasing the delivery to a varying degree, in proportion to
the temperature reached by the coolant.

Injection timing electronic test

The advance (start of delivery, expressed in degrees) may be
different from one injection to the next, also differentiated
from one cylinder to another. It is calculated, similarly to the
delivery, in relation to the engine load (accelerator position,
engine speed and air introduced).
The advance is appropriately corrected:

-

in phases of acceleration;

-

according to the water temperature.

And also to obtain:

-

lower emissions, noise and overloading;

-

better vehicle acceleration.

An extremely high advance is set on starting, depending on the
water temperature.
Feedback from the start of delivery is supplied by the change
in impedance of the injector solenoid valve.

Speed governor

The electronic speed governor has both features of
governors:

-

idling and top speed

-

all speeds

It is stable in ranges where conventional, mechanical governors
are imprecise.

Engine starting

During the first few turns of the engine, the timing and cylinder
no. 1 recognition signals (flywheel sensor and camshaft sensor)
are synchronized.
The accelerator pedal signal is ignored on starting. Starting
delivery is set only according to water temperature, by a
special map.
When the control unit detects such speed and acceleration of
the flywheel as to be able to consider the engine started up
and no longer driven by the starter motor, it re-enables the
accelerator pedal.

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