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Iveco Daily. Manual - part 177

Revi - February 2005

Figure 273

75574

771034

Pressure regulator

75575

Figure 274

Accurately clean high pressure pump.
Take off screws (2) and unthread pressure regulator (3) from
high pressure pump.

88406

Figure 274/1

Replacing pressure regulator

Figure 274/2

88407

Accurately clean the seat (

→) of pressure regulator and the

connection surface (

→) of the regulator.

For cleaning, do not use a tool which could damage
the surfaces and pay attention that impurities are
not introduced into channels.

NOTE

88408

Mount new seal rings (1 and 2) on pressure regulator (3) and
lubricate the rings with vaseline.

Figure 274/3

The fuel pressure regulator is mounted on the low-pressure
circuit of the CP3 pump. The pressure regulator modulates
the amount of fuel sent to the high-pressure circuit according
to the commands received directly from the engine control
unit. The pressure regulator is mainly composed of the
following components:
- connector
- casing
- solenoid
- pre-load spring
- shutter cylinder.
When there is no signal, the pressure regulator is normally
open, therefore with the pump providing maximum delivery.
The engine control unit, via the PWM (Pulse Width
Modulation) signal, modulates the change in fuel flow rate in
the high-pressure circuit by partially closing or opening the
sections of passage of the fuel in the low-pressure circuit.

Operation

1. Solenoid — 2. Magnetic core — 3. Shutter cylinder —

4. Fuel inlet — 5. Fuel outlet.

When the engine control unit governs the pressure regulator
(via PWM signal), the solenoid (1) is energized that, in its turn,
generates the movement of the magnetic core (2). The shift
of the core causes the shutter cylinder (3) to move axially,
choking the flow of fuel.

1. Solenoid — 2. Magnetic core — 3. Pre-load spring —

4. Shutter cylinder.

When the solenoid (1) is not energized, the magnetic core is
pushed into the rest position by the pre-load spring (3). In this
condition, the shutter cylinder (4) is in such a position as to
offer the fuel the greatest section of passage.

604

F1C ENGINE

AILY

Base - May 2004

72592

Figure 275

Figure 276

72593

The by-pass valve (1) trips when overpressure is generated at
the outlet B. The pressure, overcoming the elastic resistance
of the spring of the valve (1), sets the outlet in communication
with the inlet via the duct (2).

Conditions of bleeding

72594

The by-pass valve (1) trips when, with the engine switched off,
you want to fill the supply system via the priming pump. In this
situation, the by-pass valve (2) opens, due to the effect of the
inlet pressure, and the fuel flows out via the outlet B.

Figure 277

Figure 274/4

Mount pressure regulator (1) on high pressure pump (2).

88409

Mounting operation must be performed keeping
the regulator perpendicular to connection plane
without angling it, in order not to damage seal rings
(1-2, Figure 260).

NOTE

88410

Screw up screws (1) and tighten them at 6

÷ 7 Nm (0.6 ÷ 0.7

kgm) torque.

Figure 274/5

Where pressure regulator is replaced on the engine
mounted on the vehicle, it is needed, after
replacement, to check that there are no fuel leaks
after an engine working period.

MECHANICAL SUPPLY PUMP

Normal working condition

A. Fuel inlet from the tank — B. Fuel outlet to the filter —

1, 2 By-pass valves in closed position.

The function of the gear pump, mounted on the rear of the
high-pressure pump, is to supply the high-pressure pump. It is
governed by the shaft of the high-pressure pump.
In normal working conditions, the flow of fuel inside the
mechanical pump is shown in the figure.

Conditions of outlet overpressure

NOTE

Revi - February 2005

F1C ENGINE

605

AILY

Revi - February 2005

88418

Figure 278

774510

Hydraulic accumulator (rail)

The hydraulic accumulator is fitted on the cylinder head on the
suction side.

With its volume of approximately 23 cm

it dampens the

pressure ripples of the fuel due to:

the operation of the high-pressure pump;

the opening of the electro-injectors.

On the hydraulic accumulator (1) there is the fuel pressure
sensor (2).

775010

ELECTRO-INJECTORS

Figure 279

The electro-injectors have high-pressure supply (up to 1600
bar) and recirculation at atmospheric pressure, necessary for
the diesel used to operate the pilot valve.
The temperature of the diesel put back into circulation by the
electro-injector can get very high (approximately 120

°C).

The head of the electro-injector has a fitting for the electrical
connector.
They are mounted on the cylinder head and operated by the
injection control unit.
The electric injector can be subdivided into two parts (see
Figure 280):

The electro-injector can be divided into two parts:

actuator/jet composed of pressure rod (1), pin (2) and
nozzle (3);

control solenoid valve composed of coil (4) and pilot
valve (5).

75588

Figure 280

1 Pressure rod — 2 Pin — 3 Nozzle — 4 Coil — 5 Pilot valve —

6 Ball shutter — 7 Control area — 8. Pressure chamber -

9 Control volume — 10 Low-pressure fuel return —

11 Control pipe — 12. Feeding pipe - 13 Electrical

connection — 14 High-pressure fuel inlet fitting — 15 Spring.

50704

Operation

Electro-injector operation can be broken down into three
phases:
-

”rest position”

The coil (4) is de-energised and the shutter (6) is in closed
position and does not allow the fuel to get in the cylinder, Fc
> Fa (Fc: due to the fuel pressure operating the rod (1) control
area (7). Fa: due to the line pressure operating in the pressure
chamber (8).
-

”start of injection”

The coil (4) is energized and causes the shutter (6) to rise.
The fuel of the control volume (9) flows off towards the return
manifold (10) causing a drop in pressure in the control area
(7).
At the same time, the line pressure through the fuel pipe (12)
exerts in the pressure chamber (8) a force equal to Fa > Fc
and thus makes the pin (2) lift and so the fuel gets in the
cylinders.
-

”end of injection”

The coil (4) is de-energized and makes the shutter (6) return
to its closed position. This recreates such a balance in the
forces as to make the pin (2) return to its closed position and
consequently end injection.

606

F1C ENGINE

AILY

Base - May 2004

Figure 281

ELECTRIC/ELECTRONIC COMPONENTS
766161

Electronic control unit EDC 16

The control unit is a ”flash EPROM” and so it can be
reprogrammed from outside without changing the hardware.
It processes the signals from the sensors by applying software
algorithms and controls the actuators (especially the
electro-injectors and pressure regulator).
The injection control unit has the absolute pressure sensor
built in to further improve the control of the injection system.
The control unit is mounted on the left-hand side of the engine
bay and is connected to the vehicle’s wiring harness by two
60-pin connectors:

60-pin connector A for the components on the engine

94-pin connector K for the components on the vehicle

In addition to handling the operation of the system described
under the relevant heading, the electronic control unit is
interfaced with the other electronic systems on the vehicles
such as ABS — EBD cruise control, speed limiting device,
immobilizer (IVECO CODE), EGR and glow plugs.

85711

Figure 282

761917

Glow plug electronic control unit

The engine control unit, in the phase of:

starting

after-starting

times the operation of the glow plug control unit according to
the engine temperature.

75578

The spark plug control takes place through the spark plug
pre-warming

control

unit

according

the

engine

temperature under the direct control of the engine control
unit EDC 16.

The pre-heating control unit contains an “intelligent”
contactor that sends feedback to the control unit that is thus
informed about any fault with the pre-heating control unit or
shorting to earth of the glow plugs.

761915

Glow plugs

Figure 283

75579

CONTROL VALUES

With a constant supply voltage of 11 V:

max. current drawn

18 A

in 5 sec.

±1.5 A

in 30 sec.

±0.9 A

temperature after 7 sec.

850

°C

tightening torque

8-10 Nm

SENSORS

Engine speed sensor

It is an inductive sensor and is positioned on the phonic wheel
fitted on the front end of the drive shaft
It generates the signals resulting from the magnetic flow lines
which close through the teeth of the phonic wheel.
Tooth number 58.
The electronic control unit uses this signal to measure the
speed of rotation of the engine, its angular position and to
operate the electronic rev counter.
If this signal fails the rev counter will not work.

Camshaft timing sensor

It is an inductive sensor and is positioned on the camshaft gear
of the suction valves.
It generates the signals resulting from the magnetic flow lines
which close through a slot on the gear itself.
The signal generated by this sensor is used by the electronic
control unit as a redundant signal to measure the different
engine speeds.

Revi - February 2005

F1C ENGINE

607

AILY

Content .. 175 176 177 178 ..