2000 FIAT MAREA Ok pump

Fuel feed system
Engine Marea- Marea Weekend 9 ™
2000 range (Q)
10.
Control of idle speed
On the basis of signals from the rpm sensor and engine coolant temperature sensor, the injection control
unit controls the pressure governor and alters the injector control times to maintain idle speed stable at all
times.
Under certain conditions, the idle speed control unit also considers battery voltage.
Control of maximum speed limitation
According to rpm level, the injection control unit limits maximum speed by means of two types of inter­
vention:
- as maximum speed approaches, it reduces the amount of fuel injected to reduce line pressure;
- when maximum speed is exceeded, it inhibits operation of the auxiliary pump and injectors.
Control of maximum torque limitation
On the basis of rpm level, the injection control unit computes limit torque and maximum permitted fume
index parameters on the basis of predefined, stored maps.
It then corrects the above parameters using engine coolant temperature and car speed data. The resulting
values are then used to modulate the amount of fuel to be injected by adjusting the pressure regulator and
injectors.
Control of fuel temperature
The injection control uint is kept constantly informed of fuel temperature by a sensor on the return mani­
fold.
If fuel temperature exceeds a set value (about 110 °C), the control unit reduces line pressure by adjusting
the pressure governor, leaving injection times unaltered.
Control of coolant temperature
The injection control unit is constantly informed of coolant temperature by a sensor on the thermostat.
If engine coolant temperature or air conditioning fluid pressure exceeds certain levels, the control unit
performs the following actions:
- It reduces the amount of fuel injected by adjusting the pressure governor and injectors (power reduc­
tion);
- it controls the engine radiator cooling fan.
Control of glow plugs
The injection control unit controls operation of the glow plug preheating control unit to bring the tem­
perature in the combution chambers up to levels that promote fuel self-ignition and thus make start-up
easier.
The control unit controls the operation of the glow plug control unit for a certain time both before (pre­
heating) and after (postheating) engine start-up and also controls activation of the warning light on the
control panel.
Preheating, postheating and glow plug warning light activation times vary according to engine coolant
temperature.
4 Publication no. 506.763/24

Marea- Marea Weekend 9 ™
2000 range ©
Engine
Fuel feed system
10.
DIAGRAM SHOWING INFORMATION FLOW BETWEN THE INJECTION CONTROL UNIT AND
SENSORS/ACTUATORS
1. Auxiliary fuel pump
2. Variable geometry turbocharger control sole­
noid
3. Climate control compressor
4. Electric EGR valve
5. Rev counter
6. Engine radiator fan
7. Glow plug preheating control unit
8. Potentiometer on accelerator pedal
9. Brake and clutch pedal switches
10. Fuel pressure sensor
11. Intake air flow and temperature sensor (de-
bimeter)
12. Coolant temperature sensor
13. Fuel temperature sensor
14. Pressure relief sensor
15. Timing sensor
16. Rpm sensor
17. Vehicle speed signal
18. Battery
19. Four stage pressure switch
20. Fiat CODE control unit
21. Diagnostic socket
22. Fuel pressure regulator
23. Injectors
24. Throttle valve control solenoid
25. Glow plug preheating warning light
26. Injection system failure warning light
Copyright by Fiat Auto 1

Marea- Marea Weekend 9 ™
2000 range ©) Fuel feed system
Engine
10.
Compents of injection system wiring diagram
1. Vehicle speepd
2. Rev counter
3. Engine radiator fan low speed relay
4. Radiator fan high speed activation relay
5. Potentiometer on accelerator pedal
6. Timing sensor
7. Fuel pressure sensor
8. EGR system modulator solenoid
9. Fuel pressure regulator
10. Glow plug preheating warning light on control panel
11. Injection system failure warning light
12. Air conditioning system relay
13. Coolant temperature sensor
14. Rpm sensor
15. Fuel temperature sensor
16. Diagnostic socket
17. Fiat CODE control unit
18. Four stage pressure switch
19. Injection electronic control unit
20. Pressure relief sensor
21. 7.5A fuse protecting electronic injection system ( + 15 power supply from ignition switch)
22. 7.5A fuse protecting electronic injection system ( + 30 power supply from ignition switch)
23. Main injection system relay
24. 30A fuse protecting injection system
25. Auxiliary fuel pump relay
26. Glow plug preheating control unit
27. Intake air flow and temperature sensor (debimeter)
28. Brake pedal switch
29. Clutch pedal switch
30. Ignition switch
31. Battery
32. Inertia switch
33. Auxiliary fuel pump (submerged in tank)
34. 60A fuse protecting glow plug control unit
35. Cylinder no. 1 glow plug
36. Cylinder no. 2 glow plug
37. Cylinder no. 3 glow plug
38. Cylinder no. 4 glow plug
39. Cylinder no. 1 injector
40. Cylinder no. 2 injector
41. Cylinder no. 3 injector
42. Cylinder no. 4 injector
43. Throttle valve control solenoid
44. Variable geometry turbocharger control solenoid
45. Diesel filter heater relay
Copyright by Fiat Auto 9

Engine Marea- Marea Weekend 9 ™
Fuel feed system 2000 range @
10.
ELECTRONIC INJECTION CONTROL UNIT
The control unit processes signals from the various sensors by applying software algorithms and controls
the actuators accordingly (particularly the injectors and pressure regulator) to achieve the best possible
engine service conditions.
The control unit is "flash E.P.R.O.M." type, i.e. it can be reprogrammed from outside without andy need
to adjust the hardware.
The injection control unit contains a built-in absolute pressure sensor and is connected to the wiring by
means of a 121 pin connector.
Control unit connection identification (PIN-out)
4 5 43 24 6 25 96 106 113 105 119 120 121
1 Earth 25 Not connected
2 Earth 26 Not connected
3 Earth 27 Not connected
4 Actuator power supply 28 Not connected
5 Injector/ECU power supply 29 Not connected
6 Not connected 30 Not connected
7 Not connected 31 Not connected
8 Not connected 32 Not connected
9 Not connected 33 Not connected
10 Not connected 34 Not connected
11 Fiat CODE 35 Not connected
12 Not connected 36 Not connected
13 Injection relay
14 Glow plug control
15 Throttle body solenoid
16 EGR valve
17S VGT solenoid
18 Air conditioner relay
19 Radiator fan high speed relay
20 Radiator fan low speed relay
21 Diagnostic warning light control
22 Glow plug activation control
23 Not connected
24 Auxiliary fuel pump relay
10 Publication no. 506.763/24

Engine
Fuel feed system
JTD Marea- Marea Weekend 0
2000 range ©
10.
FUEL SUPPLY CIRCUIT
Operationally-speaking, the fuel supply circuit is divided into a low pressure circuit and a high pressure
circuit.
The low pressure circuit consists of a tank, multifunction valve, auxiliary fuel pump submerged in the tank
and a return manifold.
The high pressure circuit consists of a radialjet pressure pump, delivery manifold and injectors.
1. Fuel tank
2. Submerged fuel pump (auxiliary) with fuel
level gauge control
3. Multifunction valve
4. Pressure pump control pulley
5. Diesel filter cartridge
6. Pressure pump
7. High pressure pipe
8. Delivery manifold (rail)
9. Injectors
10. Fuel recirculation pipe (injector return)
11. Return manifold
12. Pressure regulator
13. Fuel temperature sensor
14. Fuel pressure sensor
15. Diesel heater
16. Fuel temperature sensor
17. Sensor indicating presence of water in fuel
filter
18 Publication no. 506.763/24

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
Copyright by Fiat Auto 19

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
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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