fuel pressure FIAT MAREA 2001 1.G Owner's Manual

Marea- Marea Weekend 9 ™
2000 range (Q)
4F019XJ01
1. Impeller
2. Volumes
3. Intake port
4. Outlet port
5. Rollers
6. Outer race
7. Pressure relief valve
4F019XJ02
Engine
Fuel feed system
10.
SUBMERGED FUEL PUMP ASSEMBLY
(AUXILIARY) AND LEVEL GAUGE CON­
TROL
The assembly consists mainly of:
- a roller-type fuel pump;
- a fuel level gauge;
- a fuel filter
The submerged fuel pump is volumetric type
with rollers and a motor with brushes and
permanent magnet excitation.
Impeller (1) is driven by the electric motor to
turn and create volumes (2) that move from
intake port (3) to outlet port (4).
These volumes are delimited by rollers (5) that
adhere to outer race(6) as the motor turns.
The pump is fitted with two valves: a check
valve to prevent the fuel circuit emptying
(with the pump off); a second pressure relief
valve (7) that short-circuits the outlet to the
inlet when pressures exceed 5 bars.
FUEL FILTER
The fuel filter is located in the engine bay.
The filter is cartridge type with a filter element
(1) made up of a pack of paper discs with a
filtering area of some 5300 cm 2 and a filter
gauge of 4 - 5 microns.
The filter is equipped with a fuel preheating
device (2) controlled by the engine control
unit via a relay.
The control unit activates or deactivates the
diesel filter on the basis of a diesel tempera­
ture signal sent by sensor (3) on the filter.
A plug (4) screwed to the base of the fuel
filter cartridge is used to drai off the water.
The plug incorporates a sensor for the detec­
tion of water in the diesel filter connected to a
warning light on the instrument panel.
1. Filter cartridge
2. Diesel preheating device
3. Diesel temperature sensor
4. Water drain plug with sensor to detect
presence of water in diesel filter
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Engine
Fuel feed system
JTD Marea-Marea Weekend @
2000 range ©
10.
7^ £3
PRESSURE PUMP
The pressure pump is radialjet type with three
radial pistons (total capacity 0.657 cc). It is
controlled by a timing belt with or without
timing requirements.
Each pump unit consists of:
a piston (5) opered by a cam (2) integral with
the pump shaft (6);
a plate-type intake valve (3);
a delivery ball valve (4).
The pressure pump must be supplied at a
pressure of at least 0.5 bars; and for this rea­
son the fuel system is equipped with an aux­
iliary pump submerged in the tank.
The pressure pump is lubricated and cooled
by the diesel fuel via channels and is able to
deliver a maximum pressure of 1350 bars.
1.
2.
3.
4.
5.
6.
7.
8.
Cylinder
Cam
Plate-type intake valve
Ball-type delivery valve
Piston
Pump shaft
Diesel intake connection -
from fuel filter
Diesel delivery connection
to manifold (rail)
Diesel delivery connection
recirculation
low pressure
high pressure
low pressure
PRESSURE REGULATOR
FILTER
The fuel pressure regulator is fitted to the
pressure pump and controlled directly by the
injection control unit. It regulates fuel feed
pressure to the injectors.
The pressure regulator consists mainly of the
following parts:
1. Ball plunger
2. Pin
3. Valve
4. Preload spring
5. Coil
6. Body
7. Anchor
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Marea- Marea Weekend <§l ™
2000 range ©
Engine
Fuel feed system
TZZZZZZZZZZZZZZZZZZb
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10.
MULTIFUNCTION VALVE
The multifunction valve is located on the fuel
tank and performs the following functions:
- tank pressurisation
- ventilation
- seal if the car rolls over
Tank pressurisation
Tank pressurisation is maintained at a level be­
tween 55 and 75 mbars by means of a valve
mounted on a sealing rim.
The valve is supported by a steel plate and held in place by a spring.
When tank pressure exceeds a specified level, it overcomes spring resistance and allows the valve to rise
so that vapours can flow out.
When the pressure returns to within specified limits, the valve closes again
Ventilation
Under certain car service conditions, a vacuum may build up in the tank due to the effect of:
- heat changes;
- fuel consumption
in this case, the valve's function is to make up pressure inside the tank by letting air into the tank.
If this function is not performed correctly, the car may judder or stall due to difficulties in supplying the
pump.
Seal if the car rolls over
The roll-over function prevents fuel emerging from the tank if the car rolls over or tilts to a great extent.
During normal car operation (bends, acceleration, braking etc.), the fuel slops about and may emerge.
The highly-sensitive roll-over valve prevents this happening.
DELIVERY MANIFOLD (RAIL)
The delivery manifold (rail) is fitted to the cylinder head on the intake side.
Its volume damps fuel pressure fluctuations due mainly to:
- operation of the pressure pump;
- injector opening.
A fuel pressure sensor is fitted in the middle of the delivery manifold.
Hydraulic connections (high pressure) are via special steel pipes.
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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
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Engine
Fuel feed system
JTD Marea- Marea Weekend 9
2000 range @
10.
Operation at high rotation speeds
When the engine speed is increased, the ki­
netic energy of the exhaust gases increases
gradually.
As a result, the speed of the turbine (5) in­
creases and consequently the supercharging
pressure.
The VGT solenoid valve (2) operated by the
injection control unit (1), through the actuator
(4) causes the moving vanes to change posi­
tion until the maximum opening position is
reached.
1. Injection control unit
2. VGT solenoid valve
3. Vacuum reservoir
4. Pneumatic actuator
5. Turbine
There is therefore an increase in the passage
sections and consequently a slowing down in
the flow of exhaust gases which pass through
the turbine (1) at the same speed or slower
than the low speed conditions.
The speed of the turbine (1) decreases and
settles down at a suitable vaule for the correct
operation of the engine at high speeds.
1. Turbine
2. Moving vanes
3. Pneumatic actuator
4. Rotary seal
TURBOCHARGER (1910 JTD 100 CV)
It basically consists of two impellers (1) on
one shaft (2) which rotates on floating bear­
ings lubricated by a duct (3) from the engine
lubrication circuit.
The oil used dissipates some of the large
amount of heat given off by the exhaust gases
at the turbine.
There is a waste gate valve (4) fitted on the
turbocharger, operated by a pneumatic actua­
tor (5), that makes it possible to shutter the
flow of exhaust gases to the turbine, accord­
ing to the engine power/torque requirements.
The pneumatic actuator is controlled by the en­
gine management control unit via a solenoid
valve.
* The turbocharger used on the 1910 JTD 100 CV version is the fixed geometry type.
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Engine Marea- Marea Weekend IP ™
Fuel feed system 2000 range o
10.
The EGR valve consists of:
- a Pierburg EGR solenoid (1) operated by engine management unit (2)
- a pipe from the exhaust manifold (4) (from which the exhaust gases flow)
- an air-water heat exchanger (3) (that lowers exhaust gas temperature)
- a pipe connected to throttle body (5) to which exhaust gases are admitted
4
Operation
With coolant temperature > 20°C and engine speeds between 800 and 3000 rpm, the engine management
unit controls the EGR solenoid by means of a square wave signal.
Changes in this signal allow the EGR coil to move a plunger and thus modulate the flow of exhaust gas
from the exhaust manifold to the intake manifold; this achieves two results:
- less air is taken in
- combustion temperature is lowered (due to the presence of inert gases), thus reducing the formation of
NOx (nitrogen oxides).
The engine management control unit is constantly informed of recirculation gas quantity via data from the
debimeter. If the intake of a given quantity of air (Qam) is required for a given rpm and the level sent by
the debimeter (Qar) is lower, the difference (Qgr) is the amount of gas recirculated.
Qam - Qar = Qgr
Qam = stored theoretical air quantity
Qar = actual air quantity
Qgr = recirculated gas quantity
An atmospheric pressure signal is used in controlling the EGR valve to detect when the car is being driven at
altitude. The recirculation gas quantity can then be reduced to prevent engine fumes.
28 Publication no. 506.763/24

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.
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Engine
Fuel feed system
Marea- Marea Weekend @ ™
2000 range ©
PRESSURE REGULATOR
NOTE During the operations of removing-
refitting the pressure regulator, work
in extremely clean conditions.
Removing
- If the vehicle is equipped with a shield un­
der the engine, remove it.
1. Remove the engine oil filler plug (1), then
undo the fixing nuts (2) and remove the
sound insulation cover (3).
2. Undo the bolts (1) fixing the retaining
bands for the injector wiring.
Disconnect the electrical connectors (2) for
the injectors and place the wiring to the
side.
- Release the injection cable loom from the
retaining bands.
3. Undo the nuts (1) fixing the fuel return
manifold pipe (2) to the intake manifold.
Place the fuel return manifold pipe to the
side.
4. Disconnect the electrical connector (1) for
the pressure regulator, then undo the bolts
(2) fixing the regulator to the pump.
36 Print n° 506.763/25

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.
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Electrical equipment
Instrument panel
Marea-Marea Weekend
2000 range ©
55.
INSTRUMENT PANEL (excluding C.A.)
3 4 56789 10 11 12
21 20 1918 17 24 16 15 14 13 23 22
Front side
1. Fuel level gauge
2. Fuel reserve warning light
3. Speedometer
4. ABS failure warning light
5. Brake pad wear warning light
6. Left direction indicator warning light
7. Side lights warning light
8. Right direction indicator warning light
9. Main beam warning light
10. Low brake fluid level and handbrake ap-
plied/EBD system failure warning light
11. Rev counter
12. Engine coolant temperature gauge
13. Air Bag fault warning light
14. Brake light failure warning light
15. Doors open warning ilght
16. Trip counter/mileometer/outdoor tempera­
ture gauge
17. Low engine oil pressure warning light
18. Generator warning light
19 Injection system failure warning light
20. FIAT CODE system warning light
21. Heater plugs warning light
22. Seat belt warning light
23. Water in diesel filter warning light
24. EOBD warning light
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