Marea- Marea Weekend & Engine
2000 range (§) Fuel feed system
ENGINE MANAGEMENT SYSTEM
Foreword
The Marea-Marea Weekend 1998 20v is equipped with a 5 cylinder in line engine with 20 valves, 1998
cc, twin overhead camshaft and a Bosch ME3.1 integrated electronic injection/ignition system.
The fuel system differs from the one described for the 1998 20v "99 range" version through the addition
of several variants to make it compatible with the EEC Stage 3 EOBD regulations.
The main modifications to the system can be summarized as follows:
- Catalytic converter near the exhaust manifold to take maximum advantage of the heat of the gases.
- Two Lambda sensors, one upstream (front) and one downstream (rear) which check the quality of the
exhaust gases and the operation of the catalyzer.
- Adoption of an accelerometre sensor on the right shock absorber turret, used to distinguish between
engine torque variations doe to the uneveness of the road surface and those due to failed ignition in
the combustion chamber (misfire).
- Adoption of a timing sensor on the inlet side timing pulley.
- Multi-purpose valve on the tank to prevent leaks.
- Adoption of raipd attachment connectors for the anti-evaporation system pipes.
- Cap on the fuel filler with an attachment cable.
For further information on the fuel system, refer to publication 507137.
DIAGRAM SHOWING ENGINE EXHAUST ASSEMBLY
4F001WJ01
Key
1. Exhaust manifold
2. Catalytic converter
3. Front Lambda sensor
4. Rear Lambda sensor
5. Silencers
Copyright by Fiat Auto 1
Engine
Fuel feed system
Marea-Marea Weekend ®> *»
2000 range @)
10.
LOCATION OF INJECTION/IGNITION SYSTEM COMPONENTS
Key
1. Variable valve timing control solenoid
2. Injectors
3. Fuel vapour cut-out solenoid valve
4. Injection/ignition control unit
5. General system protective fuse
6. Flow meter/air temperature sensor
7. Motorized throttle body
8. Engine coolant temperature sensor
9. Vehicle speed sensor
10. Variable geometry manifold actuator solenoid
valve
11. RPM sensor
12. Front Lambda sensor connector
13. Ignition coil
14. Timing sensor
15. Rear Lambda sensor connector
16. Detonation sensors
17. Accelerometer
LOCATION OF DIAGNOSTIC SOCKET
The diagnostic socket for the analysis of the en
gine management system is located under the
junction unit in the dashboard. This socket also
makes a connection with the diagnostic equip
ment (Examiner or other instruments) for the
other electronic control units on the vehicle.
It is a "standardized" 16-way diagnostic socket
which can be connected to the diagnostic equip
ment using the "MPX97" adaptor.
2 Print n° 506.763/23
Marea- Marea Weekend 9 \) JTD
2000 range O
Engine
Index
FUEL SYSTEM
- Introduction
- System management strategies
- Fuel system functional diagram
- Diagram showing information ente
ring/leaving the control unit and
sensors/actuators
INJECTION SYSTEM WIRING DIA
GRAM
- Injection electronic control unit
- Rpm sensor
- Timing sensor
- Air flow meter
- Injectors
- Engine coolant temperature sensor
- Fuel temperature sensor
- Fuel pressure sensor
- Heater plugs control unit
- Accelerator pedal potentiometer
- Brake pedal switch
- Clutch pedal switch
- Excess pressure sensor
- Atmospheric pressure sensor
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2
8
10
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13
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16
16
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17
17
THROTTLE CASING
- Removing-refitting
E.G.R. VALVE
- Removing-refitting
E.G.R. VALVE SELF-ADJUSTMENT
MOTOR
- Removing-refitting
E.G.R. VALVE HEAT EXCHANGER
- Removing-refitting
SOLENOID VALVE ON VACUUM
RESERVOIR FOR THROTTLE CA
SING PNEUMATIC VALVE
- Removing-refitting
VACUUM RESERVOIR
- Removing-refitting
10.
page
30
31
32
32
34
34
FUEL SUPPLY CIRCUIT 18
- Immersed (auxiliary) pump and fuel
gauge assembly 19
- Fuel filter 19
- Pressure pump 20
- Fuel pressure regulator 20
- Multifunction valve 21
- Supply manifold (rail) 21
- Inertia safety switch 22
AIR SUPPLY CIRCUIT 23
- Throttle case 24
- Turbocharger 25
SUPERCHARGING PRESSURE
CONTROL SOLENOID VALVE
- Removing-refitting 35
FUEL FILTER
- Removing-refitting 35
PRESSURE REGULATOR
- Removing-refitting 36
EMISSION CONTROL DEVICES 27
- Oxidizing catalytic converter 27
- Exhaust gas recirculation circuit
(EGR) 27
- Recirculation circuit for crankcase
vapours (blow-by) 29
Copyright by Fiat Auto VI 01 Cancels anil replaces
Marea- Marea Weekend © ™ Engine
2000 range Q Fuel feed system
10.
FUEL SYSTEM
INTRODUCTION
Marea and Marea Weekend 1.9 JTD cars are equipped with a 4 cylinder in line, 1910 cc turbodiesel en
gine with two valves per cylinder, an overhead camshaft, turbocharger and intercooler and electronic in
jection.
The fuel system ensures correct engine operation and can be divided into the following subsystems:
- Fuel feed circuit with common rail injection;
- air feed circuit;
- exhaust circuit;
- blow by vapour recirculation circuit;
- Exhaust Gas Recirculation (EGR) circuit
Operation of the various circuits making up the fuel system is optimised by an electronic control system
managed by a special control unit.
The main feature of the fuel system is common rail fuel injection. Common rail is a higher pressure elec
tronic injection system for fast direct injection diesel engines.
The main features of the common rail system are as follows:
- availability of high injection pressures (up to 1350 bars);
- possibility of modulating these pressures (from a minimum of 150 bars to a maximum of 1350 bars)
independently of engine speed (rpm) and engine load;
- ability to operate at high engine speeds (up to 6000 rpm);
- precise injection control (injection advance and duration);
- reduced fuel consumption;
- reduced emissions.
FUEL SYSTEM MANAGEMENT STRATEGIES
The management program (software) is stored inside the control unit memory and consists of a series of
strategies, each of which manages a precise system control function.
Through the use of information providd by the various sensors (input), each strategy processes a set of
parameters based on data stored in special control unit memory areas. It then controls system actuators
(output), i.e. the devices that allow the engine to operate.
The main purpose of these management strategies is to determine the exact amount of fuel to be injected
into the cylinders with timing (injection advance) and pressure designed to achieve the best possible en
gine performance in terms of power, fuel consumption, fumes, emissions and handling.
The main system management strategies are essentially as follows:
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of injected fuel quantity;
of injection advance;
of injection pressure;
of auxiliary fuel pump;
of injection during over-run (cut-off);
of idle speed;
of maximum speed limitation;
of maximum torque limitation;
of fuel temperature;
of engine coolant temperature;
of air turbocharging pressure;
of glow plugs;
of exhaust fumes;
of exhaust gas recirculation (EGR);
of climate control system activation;
control of engine immobiliser operation (Fiat
CODE);
self-diagnosis
Copyright by Fiat Auto 1
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
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
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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
20 Publication no. 506.763/24