2001 FIAT MAREA Electric

Marea- Marea Weekend • *» Engine
2000 range (§) Fuel feed system
10.
Pages
FUEL FEED SYSTEM
- Engine management system 1
- Diagram showing engine exhaust assem­
bly 1
- Fuel anti-evaporation system ~2
- Location of diagnostic socket 2
- Location of injection/ignition system
components in the engine compartment 3
- Front Lambda sensor . 4
- Rear Lambda sensor 4
- Catalytic converter heat shield 5
- Catalytic converter 5
- Exhaust manifold 6
- Electric fuel pump with level sender unit 7
Copyright by Fiat Auto

Engine
Fuel feed system
Marea- Marea Weekend •
2000 range @
FRONT LAMBDA SENSOR
Removing
- Disconnect the negative battery terminal.
1. Disconect the electrical conection (1a), re­
lease the wiring from the retaining band
(2) and disconnect the Lambda sensor (3).
Refitting
- Position the sensor and tighten it to torque
avoiding forcing the component which
would damage it irreparably.
Apply special grease (e.g. Bosch 5
964080112) to the threaded part of the
sensor.
REAR LAMBDA SENSOR
Removing
- Position the vehicle on a lift.
- Disconnect the negative battery terminal.
2. Disconnect the electrical connection (1)
and release the wiring from the retaining
bands.
3. Raise the vehicle and disconnect the
Lambda sensor.
Refitting
- Position the sensor and tighten it to torque
avoiding force on the component which
would damage it irreparably.
Apply special grease (e.g. Bosch 5
964080112) to the threaded part of the
sensor.
- Connect the connector and renew the
Lambda senor cable fastenings.
4 Print n° 506.763/23

Marea- Marea Weekend •
2000 range ©
16v Engine
Fuel feed system
10.
1. Loosen the belt tension using the lock nut
(2) and the adjustment screw (1); then re­
lease the belt from the pulley.
2. Undo the bolts fixing the bracket for the
power assisted steering pump mounting
and detach the pump.
3. Undo the nuts fixing the exhaust manifold
to the cylinder head and detach the mani­
fold.
- To refit, reverse the order of the operations
carried out for the removal; tension the
power assisted steering pump drive belt,
using the adjustment screw; use tool
189576200 to check that the tension is
between 32 and 45 daN.
ELECTRIC FUEL PUMP WITH LEVEL
SENDER UNIT
Removing-refitting
- Disconnect the negative battery terminal.
- Lift up the lining in the luggage compart­
ment and remove the fuel pup protective
cover.
- Disconnect the electrical connection for the
electric pump assembly and the fuel supply
and breather pipes.
4. Undo the ring nut fixing the electric fuel
pump to the tank using tool 1870736000.
The gasket on the tank housing should be
replaced each time the pump drip tray is
removed-refitted.
NOTE The position of the fuel pump is fixed
and is established by a reference in
the housing in the tank which sou Id
correspond to the projection on the
pump drip tray.
Copyright by Fiat Auto 7

Marea- Marea Weekend •
2000 range ©
Engine
Fuel feed system
10.
REMOVING-REFITTING ACCELEROMETER
Removing
- Disconnect the negative battery terminal.
1. Disconnect the electrical connector (1a),
undo the fixing bolts (1b) and remove the
device (1c).
Refitting
- Reverse the order of the operations carried
out for the removal.
REMOVING-REFITTING FRONT LAMBDA
SENSOR
Removing
- Position the vehicle on a lift.
- Disconnect the negative battery terminal.
- Raise the lift.
2. Undo the lower fixing bolts (1a) and the
side fixing bolts (1b) and remove the
shield (1c) under the engine.
3. Undo the fixing nuts (1a) and remove the
lower section (1 b) of the heat shield.
4. Disconnect the electrical connector (1a)
and undo the front Lambda sensor (1b).
Copyright by Fiat Auto 3

Engine
Fuel feed system
Marea- Marea Weekend 9
2000 range ©
- Release the electrical wiring for the front
Lambda sensor from the retaining bands
and remove the sensor.
Refitting
NOTE Apply special grease (e.g. Bosch VS
14016- FT) to the threaded part ot
the sensor
- Place the Lambda sensor in position and
tighten to torque.
E Lambda sensor : 4.5 daNm
Reverse the order of the operations de­
scribed for the removal.
REMOVING-REFITTING REAR LAMBDA
SENSOR
Removing
- Position the vehicle on a lift.
- Disconnect the negative battery terminal.
1. Disconnect the electrical connector (1a)
and release the electrical wiring from the
retaining bands.
- Raise the lift.
2. Undo the lower fixing bolts (1a) and the
side fixing bolts (1b) and remove the
shield (1c) under the engine.
3. Use tool USAG 875 (1a), shown in the
diagram or a similar tool to undo the rear
Lambda sensor.
Refitting
NOTE Apply special grease (e.g. Bosch VS
14016- FT) to the threaded part of
the sensor.
- Place the Lambda sensor in position and
tighten to torque.
E Lambda sensor: 4.5 daNm
Reverse the order of the operations carried
out for the removal.
4 Print n° 506.763/23

Marea-Marea Weekend •
2000 range (§)
4F005WJ02
Engine
Fuel feed system
10.
REMOVING-REFITTING HEAT
SHIELD
Removing
- Position the vehicle on a lift.
- Disconnect the negative battery terminal.
1. Undo the fixing bolts (1a) and remove the
air duct (1b).
2. Open the retaining band (1a) and place the
engine coolant return pipe to the radiator
(1b) at the side in order to undo the bolts
(1c) fixing the upper section of the heat
shield.
3. Undo the upper bolts (1a) fixing the fan
and disconnect the electrical connector
(1b).
4F005WJ03
Copyright by Fiat Auto 5

Engine
Fuel feed system
Marea- Marea Weekend © ™
2000 range ©
10.
FUEL SYSTEM OPERATING DIAGRAM
1. Pressure pump
2. Electrically-controlled EGR valve
3. Flow meter
4. Pressure regulator
5. Fuel filter
6. Instrument panel
7. Glow plug preheating control unit
8. Electronic control unit
9. Injection system relay
10. Return manifold (low pressure)
11. RPM sensor
12. Glow plugs
13. Engine coolant temperature sensor
14. Potentiometer on accelerator pedal
15. Switch on brake pedal
16. Switch on clutch pedal
17. Variable geometry turbocharger
18. Timing sensor
19. Injectors
20. Fuel pressure sensor
21. Variable geometry turbocharger control sole­
noid
22. Auxiliary fuel pump
23. Glow plug preheating warning light
24. System failure warning light
25. Pressure relief sensor
26. Fuel temperature sensor
27. Throttle valve
28. Variable geometry actuator
29. Vacuum tank
30. Exhaust gas heat exchanger
2 Publication no. 506.763/24

Ma tea- Marea Weekend 9 ™
2000 range (Q) Fuel feed system
Engine
10.
Control of injected fuel quantity
The control unit controls the fuel pressure regulator and injectors on the basis of output signals from the
accelerator pedal potentiometer, flow meter and rpm sensor.
The timing and thus the injection sequence are determined when the engine is started up using signals
from the rpm and timing sensor (synchronisation stage); injection timing is then implemented using the
rpm sensor signal alone and considering a injection sequence of 1 -3-4-2.
The control unit inhibits injection in the following cases:
- fuel pressure level greater than 1500 bars;
- fuel pressure level lower than 120 bars;
- engine speed higher than 6000 rpm.
When the engine has warmed up, maximum injection duration (injector opening time) is 1500 ns, but it
can reach 3000 ns during the start-up stage.
Control of injection advance
The electronic control unit determines injection advance mainly on the basis of the quantity of fuel to be
injected.
The injection advance is then corrected on the basis of coolant temperature and speed in order to com­
pensate for ignition delays due to low temperatures in the combustion chamber during warm-up.
The optimum injection point is also processed to ensure driving comfort and emission limits laid down by
Euro 3 legislation.
Control of injection pressure
This control is of particular importance because injection pressure influences the following parameters:
- amount of fuel taken into the cylinders for the same injection time duration;
- injected fuel nebulation;
- spray penetration;
- lag between electrical control to injection and actual injection start and end times.
The above parameters engine behaviour significantly, particularly in terms of power output, exhaust emis­
sions, noise levels and handling.
The injection control unit controls the pressure governor on the basis of engine load to obtain an optimal
line pressure at all times.
When the engine is cold, injection pressure is corrected on the basis of engine speed and engine coolant
temperature to meet engine needs at different operating temperatures.
Control of auxiliary fuel pump
The auxiliary fuel pump submerged in the tank is supplied by the injection control unit by means of a relay
when the ignition key is turned on.
Fuel supply to the pump is inhibited when one of the following condition occurs:
- when the ignition has been turned on for a certain length of time without the engine running;
- if the inertia switch cuts in.
Control of injection during over-run (cut-off)
The fuel cut-off strategy is implemented when the injection control unit receives information that the ac­
celerator pedal has been released from the potentiometer.
Under these conditions, the control unit cuts off the fuel supply to the injectors and restores it before idle
speed is reached.
Copyright by Fiat Auto 3