2000 FIAT MAREA fuel pressure

Technical Data Marea-Marea Weekend
Engine: cooling system • fuel system 2000 range (§)
OO.io
COOLING
Cooling circuit coolant circulation via centrifugal pump, radiator
and two speed fan operated by engine control unit
Water pump operated via belt
fl (^+\ STA9E 1 90°H-94°C 96°+97T
^ Engagement vj^/ ?
of fan stage Z 95°+99°C (•) 101+102°C
\f Operated by v .
control unit (s\oo\ 9 85V89X 93°-H94T
• v y
v—' stage 2 90°+94°C (•) 98+99T
opening starts 81° - 85°C
Engine coolant
thermostat rnax opening 99+103°C 101DC+105'C
valve travel 9.5 mm
Fitting clearance between impeller p
vanes and pump casing j |< 0.3:1.1 mm 0.4 : 0.95 mm
Pressure for checking system water tightness 0.98 bar
Pressure for checking exhaust valve on expansion
tank cap 0.98 bar
(•) Versions with climate control
FUEL FEED SYSTEM
Make
Electronic integrated
injection-ignition
MPI - I.A.W.
Weber-Marelli
Electronic integrated
injection-ignition
MPI - BOSCH Motronic
Pump electric immersed in the tank
Output > 120 l/h
Fuel pressure regulator setting 3 bar
26 Print n° 506.763/23

Marea-Marea Weekend Technical Data
2000 range (j§) Engine: fuel system - special tools
OO.io
INTEGRATED ELECTRONIC INJECTION/IGNITION SYSTEM
COMPONENTS
Electronic control unit
Manual gearbox I.A.W. 4EF. B3
Electronic control unit
Automatic transmission I.A.W. 4EF. L1
Air pressure sensor M. Marelli TPRT 05
Fuel vapour solenoid valve M. Marelli EC2
Throttle case M. Marelli 46 SX F2
Idle adjustment actuator M. Marelli IB 02
Injector M. Marelli IWP 109
Fuel pressure regulator MARWALL RPM 84
Coolant temperature sender unit SYLEA 402.386.01
Top Dead Centre and rpm sensor M. Marelli CVM 02
Throttle position sensor (potentiometer) M. Marelli IPF 2C
Detonation sensor NGK KNE 11
Electric fuel pump (*) MARWALL ESS 291
Lambda sensor upstream of catalyzer NTK OZA 534 A1
Lambda sensor downstream of catalyzer NTK OZA 532 A1
Fuel filter MARWALL FA 5325 IN
Timing sensor SYLEA SFA 200
Ignition coil Champion BAE 920A/
BERU 0.040.100.029
SPECIAL TOOLS
(*) Use tool 1870736000 for removing-refitting the fuel pump retaining ring nut
Copyright by Fiat Auto 27

Marea- Marea Weekend
2000 range ©
Technical Data
Wheels
WHEEL ALIGNMENT
00.44
unladen vehicle (•)
camber (**)
caster (**)
front
suspension
toe-in
offset
front wheels
±3*
36' 24» ± 30'
10 57' ± 30'
-1 - 1 mm
camber (**)
U1
rear
suspension
toe-in (**)
thrust angle
rear wheels i
-0° 45' ± 30'
2 ± 2 mm
(**) Angles not adjustable
(•) With the tyres inflated to the correct pressure and the vehicle in running order with 5 litres of fuel (•) Angular values, which cannot be adjusted, used for the correct alignment of the vehicle
Copyright by Fiat Auto 41

Marea- Marea Weekend 9* Engine
2000 range (Q) Fuel feed system
10.
LOCATION OF INJECTION/IGNITION SYSTEM COMPONENTS IN THE ENGINE COMPART­
MENT
1 2345678 9
Key
1. Active charcoal filter
2. Anti-evaporation solenoid valve
3. Intake air pressure and temperature sensor
4. Engine idle adjustment stepping motor on
throttle casing
5. Throttle valve position sensor on throttle cas­
ing
6. System relay feed
7. Protective fuse
8. Throttle case
9. Maxi-fuse protecting I.E. system (EFI)
10. Speedometer sensor
11. Engine management control unit
12. Coolant temperature sensor
13. Ignition coil
14. Injectors
15. Rpm and TDC sensor
16. Timing sensor
17. Spark plugs
Copyright by Fiat Auto 3

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
page
1
1
1
2
8
10
12
13
13
14
15
15
15
16
16
17
17
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:
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
contro
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

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