Page 111 of 330

Marea- Marea Weekend 9
2000 range ©
Engine
Fuel feed system
10.
TURBOCHARGER (1910 JTD 110 CV)
The turbocharger used in the application of the
EURO 3 standards in the variable geometry
type connected to the exhaust manifold.
The turbocharger is controlled by the engine
management control unit via a duty-cycle so
lenoid valve.
The increased volumetric output for the engine
is achieved, in the case of variable geometry
compressors, through the use of:
- a centrifugal compressor (1)
- a turbine (2)
- a series of moving vanes (3)
- a pneumatic actuator (4) controlling the
moving vanes.
- asolenoid valve (5) controlling the actuator
The variable geometry turbocharger makes it
possible to:
- increase the speed of the exhaust gases in
the turbine at low engine speeds
- slow down the speed of the exhaust gases
in the turbine at high speeds.
The control of the speed (kinetic energy) of
the exhaust gases makes it possible to pro
duce increased engine torque at low speeds
and greater maximum power at high speeds.
Operation at low rotation speeds
When the engine is operating at low speeds,
the exhaust gases possses little kinetic energy:
under these circumstances a conventional tur
bine would rotate slowly, supplying a limited
supercharging pressure.
On the other hand, in the variable geometry
turbine (1), the moving vanes are in the
maximum closure position and the small pas
sage sections between the vanes increase the
speed (C) of the intake gases.
Increased intake speeds lead to increased pe
ripheral speeds (U) of the turbine and, conse
quently, the compressor.
The speed of the gases inside the impeller is
indicated by the vector (W).
1. Turbine
2. Moving vanes
3. Pneumatic actuator
4. Rotary seal
Copyright by Fiat Auto r VI-01-Cancels arwl replaces.25
Page 113 of 330

Marea- Marea Weekend 0 *° Engine
2000 range @ Fuel feed system
10.
EMISSION CONTROL DEVICES
The car is equipped with devices designed to reduce polluting emissions in accordance with Euro 3
reguirements:
- Oxidising catalytic converter (1)
- Exhaust gas recirculation circuit (EGR) (2)
- Crankcase blow-by vapour recirculation circuit (3).
4F027XJ01
OXIDISING CATALYTIC CONVERTER
The oxidising catalytic converter is a post-
treatment device used to oxidise CO, HC and
particulate and convert them to carbon dioxide
(C02) and water vapour (H20).
The catalytic converter consists of a ceramic
honeycomb case (1) with its chambers im
pregnated with platinum, a substance that
catalyses oxidation reactions.
Exhaust gases flow through the chambers and
heat the catalytic converter where they trigger
the conversion of pollutants to inert com
pounds.
The chemical reaction involved in oxidising
the CO, HC and particulate is effective at tem
peratures between 200 °C and 350 °C.
Above 350 °C, the sulphur in the diesel begins
to oxidise to produce sulphur dioxide and sul
phuric acid.
EXHAUST GAS RECIRCULATION CIRCUIT (EGR)
This system sends a proportion of exhaust gases to the intake under certain engine service conditions.
This dilutes the fuel mixture with inert gsaes to lower.peak temperature in the combustion chamber; This
helps limit the formation of nitrogen oxides (NOx) and reduces exhaust levels by 30-50%.
4F027XJ02
Copyright by Fiat Auto 27
Page 115 of 330
Marea-Marea Weekend
2000 range (j§)
1
4F029XJ02
Engine
Fuel feed system
10.
RECIRCULATION CIRCUIT FOR CRANK-
CASE VAPOURS (BLOW-BY)
The control of the oil vapour emissions is
achieved through a separator (1) (function
carried out by the tappet cover) which collects
the vapours released by the crankcase in the
pipe (2).
The difference in temperature between the
separator and the oil vapours causes partial
condensation.
The vapours which have not condensed are
sent, via the pipe (3), to the turbocharger air
intake hose.
The adjustment valve, consisting of a spring
(1) and a diaphragm (2), on the tappet cover
makes it possible to prevent intake.
When the vacuum values inside the tappet
cover exceed a pre-set limit, the diaphragm
moves downwards sealing the duct from the
crankcase.
Copyright by Fiat Auto 29
Page 117 of 330
Marea- Marea Weekend 9 *°
2000 range @)
Engine
Fuel feed system
10.
1. Undo the bolts (1) fixing the expansion
joint to the E.G.R. valve, disconnect the
pipe connecting the pneumatic valve and
the solenoid valve, then undo the bolts (3)
and remove the throttle casing.
2. At the bench, undo the bolts (1) and
separate the expansion joint from the throt
tle casing.
The pneumatic valve (2) is secured to the
throttle casing.
E.G.R. VALVE
Removing-refitting
- Remove the throttle casing, following the
description in the previous paragraph.
3. Loosen the bolts (1) fixing the pipe con
necting the E.G.R. and the heat exchanger.
4. Disconnect the electrical connection (1) for
the E.G.R. valve self-adjustment motor; undo
the bolts (2) fixing the E.G.R. valve to the
intake manifold, then lift up the valve and
remove the bolts fixing the pipe connected to
the heat exchanger (loosened previously).
Copyright by Fiat Auto VI 01 i ndate 31
Page 119 of 330
Marea- Marea Weekend 9
2000 range ©
Engine
Fuel feed system
Open the band (1) retaining the oil vapour
recovery pipe, then undo the bolts (2) fix
ing the E.G.R. valve heat exchanger
mounting bracket.
Undo the nut (1), located under the ther
mostat, fixing the heat exchanger.
Disconnect the band (1) retaining the cool
ant pipe for the heat exchanger.
Undo the bolts shown in the diagram and
remove the thermostat to allow the subse
quent extraction of the heat exchanger.
Remove the heat exchanger from the en
gine compartment.
Copyright by Fiat Auto VK01 - Update ,f 33
Page 121 of 330
Ma tea- Marea Weekend 9 m
2000 range ©)
Engine
Fuel feed system
10.
1. Undo the fixing nuts (1) and remove the
vacuum reservoir.
SOLENOID VALVE CONTROLLING
SUPERCHARGING PRESSURE
Removing-refitting
- Position the vehicle on a lift, then discon
nect the negative battery lead.
2. Working from underneath the vehicle, dis
connect the electrical connector (1) and
the pipes (2).
3. Press the retaining tab on the rear of the
mounting bracket and release the solenoid
valve.
FUEL FILTER
Removing-refitting
4. Disconnect the electrical connections (1)
from the fuel filter and the supply and re
turn pipes to the tank and the supply pipes
to the pump (2), then undo the nuts (3)
fixing the fuel filter mounting. Lift up the
filter and disconnect the electrical connec
tion (4) for the water in the diesel sensor.
Copyright by Fiat Auto oi upjdin 35
Page 123 of 330

Marea-Marea Weekend H nD Engine
2000 range (Q) Fuel feed system
10.
1. Grip the outer casing of the regulator, partly
extract it and, at the same time, rotate it so
that the fins (1) which contain the open
ings for the fixing bolts are positioned hori
zontally.
NOTA Do not grip the pressure regulator by
the electrical connector.
Insert the blades of two screwdrivers by the
fins (1) and very carefully extract the pressure
regulator.
NOTE Do not use a screwdriver or other
tools in the seal areas between the
regulator and the pressure pump.
2. Pressure regulator
1. High pressure seal (black or green)
2. Anti-extrusion seal (white)
3. Low pressure seal (black)
NOTE // the high pressure seal accidentally
remains inside the pump casing, turn
the ignition key to the ON position
(engine switched off); this will op
erate the pump shaft and a small
amount of fuel and the seal will come
out.
NOTE Do not, under any circumstances, use any tools for extracting the high pressure seal and this
could damage the inner surface of the pump.
Refitting
- Suction off any impurities present inside the pump casing.
- Check the condition of the three seals and make sure they are correctly positioned before fitting.
- Slightly lubricate the outer surface of the three seals using vaseline. Do not, under any circumstances,
lubricate the other surfaces of the pressure regulator.
- Insert the pressure regulator in its housing on the pump, pressing gently and, at the same time, rotating
the regulator until it is is contact with the surface of the pump.
NOTE Do not, under any circumstances, use a hammer or other tools when fitting the pressure regula
tor.
- Fit the two bolts fixing the pressure regulator to the pump acsing. and tighten them to a torque of
0.9±0.1 daNm.
- Reconnect the electrical connector and complete the refitting of the remaining components reversing the
order of the operations carried out for the removal.
Copyright by Fiat Auto |& yt-01 - Update 37
Page 125 of 330
Marea- Marea Weekend
2000 range CJ
Auxiliary Units
Index
Compressor ( 1596 engine)
Compressor ( 1910 JTD)
Compressor ( 1998 engine)
Specifications
50
page
1
2
3
4
FOR ANYTHING NOT DEALT WITH,
REFER TO THE BASIC MANUAL, SECTION 50.
Copyright by Fiat Auto