Iveco Daily. Manual

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 engi-
ne.

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

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, 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.

Adjusting turbine speed (for variable geometry
turbocharger - when present)

Turbine speed is adjusted by varying its geometry and is
controlled by ECU through an electric signal which powers the
pilot solenoid valve of the pneumatic actuator. ECU, according
to signals received from engine rpm sensor, intake manifold
pressure/temperature sensor and throttle sensor, processes
the feedback signal to properly modulate turbine actuator
pilot solenoid valve opening.

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 stroke 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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Cut-off

This function cuts off fuel delivery when the vehicle is
decelerating (accelerator pedal released).

Cylinder balancing

Individual cylinder balancing contributes to increasing comfort
and handling.
This function permits individual, customized control over the
delivery of fuel and the start of delivery for each cylinder, even
differently from one cylinder to another, to compensate for
the hydraulic tolerances of the injector.

The differences in flow (delivery specifications) between the
various injectors cannot be evaluated directly by the control
unit. This information is supplied by Modus reading the bar
code of each injector at the time of assembly.

Synchronization search

If there is no signal from the camshaft sensor, the control unit
is anyhow able to recognize the cylinders into which the fuel
is to be injected.
If this occurs when the engine is already running, the
combustion sequence has already been acquired, so the
control unit continues with the sequence on which it has
already been synchronized.
If this occurs when the machine is at a standstill, the control
unit energizes a single solenoid valve. Within at most 2 turns
of the crankshaft, injection will take place in that cylinder, so
the control unit just needs to get synchronized on the order
of combustion and to start up the engine.

Cold starting

If even just one of the three temperature sensors (water, air
or diesel) records a temperature lower than 10

°C, pre-post

heating is activated.
When the key makes contact the pre-heating indicator light
comes on and stays on for a length of time that varies in
relation to the temperature (while the heater at the intake
manifold inlet warms the air), then flashes. It is now possible
to start up the engine.
When the motor is running this indicator light goes out, while
the heater continues to be powered for a certain length of
time (variable) for post-heating.
If, with the indicator light flashing, the engine is not started up
within 20

÷ 25 seconds (inattention time), the operation is

cancelled so as not to run down the batteries pointlessly.
The pre-heating curve is also variable in relation to the battery
voltage.

Warm starting

If the reference temperatures all exceed 10

°C, when the key

makes contact the indicator light comes on for approximately
2 sec., for a short test, and then goes out. It is now possible to
start up the engine.

Run up

When the key makes contact, the control unit transfers the
information stored in memory when the engine was last
stopped into the main memory (see After run) and makes a
diagnosis of the system.

After run

Whenever the engine is switched off with the key, the control
unit stays powered for a few seconds by the main relay.
This makes it possible for the microprocessor to transfer some
data from the main memory (of the volatile type) to a
non-volatile memory, which can be cancelled and written over
(EEPROM), so as to make it available at the next start up (see
Run Up).
These data basically consist of:

—

various settings (engine idling adjustment, etc.);

—

settings of some components;

—

fault memory.

The process lasts a few seconds, typically from 2 to 7
(depending on the amount of data to save), after which the
ECU sends a command to the main relay and makes it
disconnect from the battery.

It is extremely important for this procedure not to
be broken off, for example by switching off the
engine with the battery cut-out, or by disconnecting
the battery cut-out before 10 seconds have passed
since switching off the engine.
If this happens, the functioning of the system is
ensured, but repeated interruptions may damage
the control unit.

NOTE

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Figure 240

The electro-injectors are supplied by the rail and their
operation is determined by the excitation of a fast
electromagnetic actuator built into the body of each
electro-injector that, by opening a gap, causes a difference in
pressure, making it possible for the needle to open.

An electronic control unit, in which the control and power
units for operating the electro-injectors are integrated, is
enabled to control the entire injection system.

Some sensors, connected to the control unit, make it possible
to determine the status of the engine and injection system, as
well as the demand for power from the driver, at any moment.

This system is completed by the possibility of operating an
EGR actuator and an actuator for a turbocharger equipped
with a waste-gate or a turbocharger with variable geometry
(if present on the engine).

Operation

A piston pump supplies diesel at a regulated pressure equal to
that of injection (up to 1350 bar).

A 2-way solenoid valve taps an adequate amount of fuel from
the pump delivery in order to regulate the pressure on the
desired value.

The diesel under pressure is accumulated in a hydraulic
accumulator (rail) that performs the function of capacity to
limit the pressure ripples.

A pressure sensor is fitted on the hydraulic accumulator (rail)
with the job of sending a signal (feedback) to the pressure
adjustment circuit.

50701

FUNCTIONAL DIAGRAM

1. 3rd pumping element exclusion device - 2. Engine speed sensor on engine flywheel - 3. High-pressure pump -

4. Pressure regulator - 5. Other actuators (thermostart, heated filter, fan control, AC control) - 6. Electronic control

unit with atmospheric pressure sensor built in - 7. Other sensors (accelerator, brake, clutch, vehicle speed, water

temperature, air temperature) - 8. From the manifold (rail) pressure sensor - 9. Fuel tank - 10. Pre-filter - 11. Motor
pump - 12. Fuel filter - 13. Filter overpressure valve - 14. Exhaust assembly with calibrated hole - 15. Pressure relief

device of hydraulic accumulator (rail) - 16. Air flow rate meter - 17. Hydraulic accumulator (rail) - 18. Electro-injectors -

19. Stroke sensor on camshaft pulley.

To thermostart
Electric circuit
Fuel at low pressure
Fuel at high pressure

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Figure 241

Specifications

Delivery pressure:

2,5 bar

Flow rate:

> 155 l/h

Power supply:

13.5 V - < 5A

Coil resistance at 20

°C:

28.5 Ohm

HYDRAULIC SYSTEM

The hydraulic system is composed of:

—

tank;

—

pre-filter;

—

electric supply pump;

—

fuel filter;

—

high pressure supply pump;

—

pressure regulator;

—

manifold (rail);

—

electro-injectors;

—

supply pipes and fuel recirculation.

773010

Fuel pump

This rotary positive displacement pump with integrated
by-pass is mounted on the suction pipe, on the left-hand side
of the chassis frame.

The fuel pump is the roller-type with positive displacement, a
brush motor with energizing by permanent magnets.
The impeller turns, driven by the motor, creating volumes that
shift from the inlet port to the delivery port.
These volumes are defined by the rollers that stick to the outer
ring when the motor turns.
The pump has two valves, a check valve to prevent the fuel
circuit from emptying (with the pump stationary) and an
overpressure valve that recirculates the delivery with the inlet
when pressures over 5 bar are produced.

50707

CROSS-SECTION OF FUEL PUMP

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Iveco Daily. Manual - part 33