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.
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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
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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
3
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
Fc
Fa
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.
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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
to
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.
11
±1.5 A
-
in 30 sec.
6
±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.
K
A
Revi - February 2005
F1C ENGINE
607
D
AILY
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