Engines Iveco C10,C13, Cursor 10, Cursor 13. Manual

EGR EXHAUST GAS RECIRCULATION SYSTEM

The exhaust gases may be partially conveyed back into the cylinders to reduce the maximum combustion temperature responsi-
ble for producing nitrogen oxides (NOx).
The exhaust gas recirculation (EGR) system, by reducing the combustion temperature, thus represents an effective NOx emis-
sion controlling system.

INTERNAL EGR ACTING ON THE INTAKE VALVES

Through a modification to the design of the intake cams, the internal EGR system enables part of the exhaust gas to be conveyed
back into the engine’s cylinders.
This type of EGR, called internal EGR, has no electronically controlled elements, the system is always active.
Its configuration requires no additional elements such as control valves, pipes or heat exchangers, so the profile of the engine
remains unchanged.
In addition to the main lobe, the intake cam presents an additional lobe (3) with respect to the configuration without EGR.
During the exhaust stroke of the cylinder concerned, this lobe opens the intake valve slightly earlier (*). In this way, part of the
exhaust gas is trapped in the intake pipe and then, during the intake stroke of the cylinder, is returned to the load of the cylinder
for the power stroke.

Figure 38

104761

1. Exhaust cams - 2. Intake cams - 3. EGR lobe - S. Exhaust pipes - A. Intake pipes.

Y: Lift of valves in mm.

Y: Regulation of engine

shaft in degrees

CURSOR ENGINES F3A

SECTION 1 - GENERAL SPECIFICATIONS

Base - May 2007

Figure 1

1. Fuel pressure damper - 2. Valve for return circuit, starts opening at 3.5 bars -

3. Valve for return circuit, starts opening at 0.2 bars.

104241

FEEDING

Fuel is supplied via a fuel pump, filter and pre-filter, 6
pump-injectors governed by the camshaft via rocker arms
and by the electronic control unit.

Return circuit

Supply circuit

CURSOR ENGINES F3A

SECTION 2- FUEL

Base - May 2007

104242

Figure 2

1. Temperature sensor - 2. Bleed valve - 3. Secondary fuel filter - 4. By-pass valve (0.3

÷ 0.4 bar) - 5. Fuel supply pump -

6. Integrated valve (3.5 bar) - 7. Pressure relief valve (5 bar) - 8. Fuel tank - 9. Priming pump - 10. Primary fuel filter -

11. Check valve (opening 0.1 bar) - 12. Heater - 13. Electronic control unit - 14. Fuel return union with valve built in

(0.2 bar) - 15. Pump-injectors.

FUEL SUPPLY DIAGRAM (ALL TYPES)

SECTION 2 - FUEL

CURSOR ENGINES F3A

Base - May 2007

73547

104243

73548

Figure 3

Figure 4

Figure 5

A. Fuel inlet — B. Fuel delivery — C. By-pass nut —

D. Fuel return from the pump-injectors —

E. Pressure relief valve — Opening pressure: 5-8 bars.

CROSS-SECTION OF THE FUEL PUMP

1. Oil and fuel leakage indicator.

Injector-pump

1. Fuel/oil seal — 2. Fuel/diesel seal — 3. Fuel/exhaust gas seal.

The injector-pump is composed of: pumping element, nozzle,
solenoid valve.

Pumping element
The pumping element is operated by a rocker arm governed
directly by the cam of the camshaft.
The pumping element is able to ensure a high delivery
pressure. The return stroke is made by means of a return
spring.

Nozzle
Garages are authorized to perform fault diagnosis solely on
the entire injection system and may not work inside the
injector-pump, which must only be replaced.
A specific fault-diagnosis program, included in the control
unit, is able to check the operation of each injector (it
deactivates one at a time and checks the delivery of the other
five).
Fault diagnosis makes it possible to distinguish errors of an
electrical origin from ones of a mechanical/hydraulic origin.
It indicates broken pump-injectors.
It is therefore necessary to interpret all the control unit error
messages correctly.
Any defects in the injectors are to be resolved by replacing
them.

Solenoid valve
The solenoid, which is energized at each active phase of the
cycle, via a signal from the control unit, controls a slide valve
that shuts off the pumping element delivery pipe.
When the solenoid is not energized, the valve is open, the
fuel is pumped but it flows back into the return pipe with the
normal transfer pressure of approximately 5 bars.
When the solenoid is energized, the valve shuts and the fuel,
not being able to flow back into the return pipe, is pumped
into the nozzle at high pressure, causing the needle to lift.
The amount of fuel injected depends on the length of time
the slide valve is closed and therefore on the time for which
the solenoid is energized.
The solenoid valve is joined to the injector body and cannot
be removed.
On the top there are two screws securing the electrical
wiring from the control unit.
To ensure signal transmission, tighten the screws with a torque
wrench to a torque of 1.36 — 1.92 Nm (0.136 — 0.192 kgm).

Fuel pump

CURSOR ENGINES F3A

SECTION 2- FUEL

Base - May 2007

Content .. 7 8 9 10 ..

Engines Iveco C10,C13, Cursor 10, Cursor 13. Manual - part 9