Iveco Daily. Manual — part 103
75531
Figure 235
TURBOCHARGING DIAGRAM
Description
The
turbocharging
system
comprises
an
air
filter,
turbocharger and intercooler.
The air filter is the dry type comprising a filtering cartridge to
be periodically replaced.
The function of the turbocharger is to use the energy of the
engine’s exhaust gas to send pressurized air to the cylinders.
The intercooler comprises a radiator included in the engine
coolant radiator and its function is to lower the temperature
of the air leaving the turbocharger to send it to the cylinders.
HOT AIR AT ATMOSPHERIC TEMPERATURE
COLD EXHAUST GAS
HOT COMPRESSED AIR
COLD COMPRESSED AIR
EXHAUST GAS
F1A ENGINE
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AILY
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Base - May 2004
75532
Figure 236
A. THROTTLE VALVE SHUT
It is basically composed of:
- a central casing housing a shaft supported by bushings at
whose opposite ends are fitted the turbine wheel and
the compressor rotor;
- a turbine casing and a compressor casing mounted on
the end of the central body;
- an overpressure relief valve fitted on the turbine casing.
Its function is to choke the exhaust gas outlet (detail B),
sending a portion of the exhaust gas straight into the
exhaust
pipe
when
the
turbocharging
pressure
downstream from the turbocharger reaches the setting.
542410
Turbocharger
75533
B. THROTTLE VALVE OPEN
Figure 237
F1A ENGINE
391
D
AILY
Base - May 2004
75534
Figure 238
Figure 239
75535
Figure 240
75536
Cover the air, exhaust gas and lubricating oil inlets and
outlets. Thoroughly clean the outside of the turbocharger
using anticorrosive and antioxidant fluid. Disconnect the pipe
(2) from the union of the pressure relief valve (1) and fit on
it the pipe of the device 99367121 (1, Figure 239).
54249
Pressure relief valve
Checking and adjusting pressure relief valve
Rest the tip of the dial gauge (1) with a magnetic base on the
end of the tie rod (2) and zero it. Using the device 99367121
(5), introduce compressed air into the valve casing (6) at the
prescribed pressure and make sure this value stays constant
throughout the check; replace the valve if it doesn’t. In the
above conditions, the tie rod must have made the prescribed
travel. On finding a different value, use the nuts (3 and 4).
Take off the nut (2).
Take out the screws (5) and detach the bracket together
with the relief valve (7) from the turbocharger.
Mount the new valve, performing the operations for
disassembly in reverse order, and register it as follows:
Screw the nut (3) onto the stem (4) of the valve down to the
end of the thread. Mount the lever (1) on the valve stem.
Using
device
99367121
(5,
Figure 239),
introduce
compressed air into the valve (7) at the prescribed pressure;
in this condition, screw down the nut (2) until the throttle
valve controlled by the lever (1) gets positioned in its seat.
Unscrew the nut (3) to bring it into contact with the lever
(1) and at the same time block the nuts (2 and 3).
Adjust the pressure relief valve (7) as described under the
relevant heading.
Afterwards, paint the nuts (2 and 3) with safety paint and
connect the pipe (6) to the valve (7), securing it with a new
retaining clamp.
Replacing pressure relief valve
On finding irregular engine operation due to the
turbocharging system, it is first expedient to
perform the checks on the turbocharger, check the
efficiency of the seals and the fixing of the couplings,
additionally checking there is no clogging in the
intake sleeves, air filter or radiators. If the
turbocharger damage is due to a lack of lubrication,
check that the oil circulation pipes are not burst or
clogged, in which case replace them or eliminate
the trouble.
NOTE
Before fitting the turbocharger on the engine, it is
necessary to fill the central body with engine
lubricating oil.
NOTE
F1A ENGINE
D
AILY
392
Base - May 2004
Figure 241
a. Brake booster vacuum circuit - b. EGR modulated vacuum circuit
1. ECU - 2. High pressure pump - 3. Coolant temperature sensor - 4. Engine rpm sensor - 5. EGR pneumatic valve - 6. Flow
meter - 7. Suction air cleaner - 8. Modulating solenoid valve - 9. Air cleaner - 10. Vacuum brake booster -11. Reservoir - 12.
Vacuum unit.
Operating principles
The ECU (MS6.3 or EDC 16) processes the data from the
atmospheric pressure sensor, coolant sensor, engine rpm
sensor, accelerator pedal potentiometer and controls the
modulating solenoid valve via a PWM signal according to
programmed settings.
The control signal output by the ECU controls the
modulating solenoid valve which puts the brake booster
vacuum circuit into communication with that of the EGR.
The vacuum created in the EGR circuit depends on the
control signal.
The vacuum acts on the pneumatic EGR valve by recalling
and lifting the shutter which normally closes the passage of
exhaust gasses to suction.
This puts the exhaust manifold into communication with the
suction manifold and part of the exhaust gasses flows into the
intake manifold.
The control signal from the ECU to the modulating valve is
cancelled during engine conditions not requiring exhaust gas
recirculation (cranking, cold engine, idling, load request, high
altitude). The solenoid valve closes the connection between
the brake booster vacuum circuit and the EGR circuit; at the
same time, atmospheric pressure is re-established in the EGR
circuit by letting in air through the specific air cleaner.
84146
EGR system operation
The EGR system is similar to that fitted on 8140.63 engines
and described in the specific system section.
Differences with respect to the previous version fitted on
8140.63 engines include: application of an exhaust gas heat
exchanger
and
air
flow
meter,
governing
system
implementing EDC MS6.3 or EDC 16, different modulating
solenoid valve and pneumatic EGR calibration values.
F1A ENGINE
393
D
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Base - May 2004
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
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