2000 FIAT MAREA Fuel pump

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
20 Publication no. 506.763/24

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.
Copyright by Fiat Auto 21

Engine
Fuel feed system
Marea- Marea Weekend W)JTD
2000 range ©
INERTIA SAFETY SWITCH
To increase car occupant safety in the case of
impact, the car is fitted with an inertia switch
located inside the passenger compartment se­
cured to the inside of the left panel.
This sensor reduces the possibility of fire (due
to emerging fuel) by deactivating the auxiliary
fuel pump that supplies the injection circuit.
The switch consists of a steel ball, fitted in a
tapered housing, kept in place by the attrac­
tion force of a permanent magnet.
In the case of violent impact, the ball is released from the magnetic detent and opens the normally closed
(NC) electrical circuit to cut off the auxiliary fuel pump connection to earth, and as a consequence the
supply to the injection system.
To restore the auxiliary pump earth connection, move back the seat and press the switch until a click is
heard.
Even after an apparently slight impact, if there is a smell of fuel or there are leaks from the fuel
system, do not turn the switch back on, but search for the fault and remedy it to prevent the risk
of fire.
'N.C. N.A. C
Inertia switch components
1. Inertia switch assembly
2. Sheath
3. Button
4. Upper side
5. Engagement side
6. Permanent magnet
7. Permanent magnet seat
8. Steel ball
C Common terminal
N.C. Normally closed contact
N.A. Normally open contact
22 Publication no. 506.763/24

Engine Marea- Marea Weekend 9*nD
Fuel feed system 2000 range (§)
10.
THROTTLE BODY
To reduce engine noise during shut-down, a throttle has been added to the intake port with the aim of
closing off the air flow to the cylinders.
Throttle valve opening or closure is controlled by an engine control unit (5) that manages a control ac­
tuator (3) on throttle body (4) via solenoid (2).
Operation
When the engine is off, the throttle is open because no vacuum is present.
When the engine is running, the throttle is open because the Pierburg solenoid is not activated and pre­
vents the vacuum reaching the pneumatic actuator.
A vacuum builds up in the tank during engine operation.
During engine shut-down (when the ignition key is turned OFF), the control unit keeps the actuator sup­
ply relay activated for a further 4 or 5 seconds and simultaneously earths the Pierburg valve. The Pierburg
valve opens to send the vacuum that has built up in the vacuum tank to the pneumatic actuator, which
closes the throttle to cut off the flow of air to the cylinders.
4F024XJ01
1. Vacuum tank;
2. Pierburg solenoid controlling throttle body
actuator;
3. Pneumatic actuator on throttle body
4. Throttle body
5. Engine control unit
6. Vacuum pump
24 Publication no. 506.763/24

Engine
Fuel feed system
Marea- Marea Weekend 9 ™
2000 range ©
SOLENOID VALVE ON VACUUM RES­
ERVOIR FOR THROTTLE CASING
PNEUMATIC VALVE
Removing-refitting
- Disconnect the negative battery lead, then
remove the sound insulation shield follow­
ing the instructions in the previous para­
graphs.
1. Disconnect the electrical connections (1)
at the fuel filter and the supply and return
pipes (2) at the reservoir and the supply
pipe to the pump, then loosen 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.
- Release the power assisted steering fluid
supply pipe from the reservoir to the pump
from the retaining band.
2. Disconnect the pipe (1) connected to the
vacuum reservoir and the pipe (2) con­
nected to the vacuum intake pipe from the
solenoid valve. Disconnect the electrical
connector (3), then undo the fixing bolts
(4) and remove the solenoid valve.
VACUUM RESERVOIR
Removing-refitting
- Disconnect the negative battery lead, then
remove the sound insulation shield and the
fuel filter, following the instructions in the
previous paragraphs.
- Release the power assisted steering fluid
supply pipe from the reservoir to the pump
from the retaining band.
3. Disconnect the pipe (1) connected to the
vacuum reservoir and the pipe (2) con­
nected to the vacuum intake pipe from the
solenoid valve. Disconnect the electrical
connector (3), then undo the fixing bolts
(4) and remove the bracket, complete with
solenoid valve, for the throttle casing
pneumatic valve.
34 VI-01 Update IN Print n° 506.763/25

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

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.
Copyright by Fiat Auto |& yt-01 - Update 37