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
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
2000 range ©
Auxiliary Units
Climate control
50
COMPRESSOR ( 1596 engine)
The compressor fitted on this version is the HR V5 variable capacity type, illustrated in the diagram below,
and consists of:
- a crankcase (7) which contains the bores in which the pistons (4) slide;
- an assembly comprising a shaft on which an inclined plate (6) is fitted on which a disc (2) guided by
a pin (5) integral with the five connecting rods (3) controlled by the pistons (4) rotates on roller bear
ings;
- a cylinder head which contains the intake and supply ducts as well as the housing for the regulation
valve (9);
- a plate (8), between the crankcase and the cylinder head, which contains the inlet and supply valves;
- a pulley assembly with an electro-magnet coupling (1).
1. Pulley with coupling
2. Disc
3. Connecting rod
4. Piston
5. Disc guide pin
6. Inclined plate
7. Crankcase
8. Valve holder plate
9. Regulation valve
10. Valve control bellows
Operation
The alternating drive required for the sliding of the pistons in the bores/liners is produced by the rotary
motion of the inclined plate (6), whilst the variation in the capacity, dependent on the piston stroke, is
chieved through the alteration in the angle of the disc (2) controlling the connecting rods (3).
The inclination of the above mentioned disc depends on the difference in pressure between the intake
duct and the inside of the compressor. This difference, measured by the bellows (10), operates the regu
lation valve (9) and consequently causes the movement of the disc (2).
When the request for conditioned air is high, the regulation valve (9) is positioned in such a way that it
uncovers an opening which places the intake side in contact with the inside of the compressor; as, in this
case, there is no difference in pressure, the compressor operates at maximum capacity corresponding to
the position of the disc illustrated in the previous section.
When the air request is less, the valve is positioned so that the supply section is in contact with the crank
case and, at the same time, it stops the flow between the latter and the intake side activated previously.
Copyright by Fiat Auto 1
Auxiliary Units
Climate control
Marea-Marea Weekend
2000 range O
50
COMPRESSOR (1910 JTD)
The compressor fitted on this version is the SANDEN SD7V16 variable capacity type.
The capacity of the compressor varies starting from the maximum value (161.3 cm^/rev) and is gradually
reduced (up to 10.4 cm^/rev) according to the system load variations. - changed outside temperature
and/or humidity conditions or sharp variations in the engine load.
This solution is defined as "unlimited variable capacity".
The compressor is the alternating piston type: the variation in capacity is achieved by tilting the connect
ing rod holder plate with a consequent variation of the piston stroke: the movement of the plate is acti
vated by an internal regulation valve according to the balance of pressure upstream and downstream of
the compressor. In particular, a low intake pressure involves the shuttering of the compressor (reduced ca
pacity), whilst a high pressure involves operation at maximum power (maximum capacity).
7 6 4 3 2
5 9
1 Diaphgram valve
2 Pistons
3 Connecting rods
4 Connecting rod plate
5 Shaft
6 Pin
7 Arm
8 Slide
9 Guide
Pa Intake pressure
Pi Pressure inside the compressor
Pm Supply pressure
Operation
The SD7V16 compressor is illustrated in the diagram; it consists of seven pistons (2) and connecting rods
(3) fastened to a connecting rod holder plate (4). The rotary motion of the plate (4), on the shaft (5)
produces the alternating movement of the pistons.
A change in the plate angle allows an alteration in capacity: maximum inclination (as in the diagram) for
maximum capacity; almost zero inclination (vertical position) for minimum capacity (virtually nil).
The plate (4) rotates around the pin (6) hinged on the shaft (5) arm (7).
The movement of the plate (4) in relation to the shaft (5) takes place by means of splining made from a
low resistance material.
The plate (4) slides below along a guide (9) via a runner (8) made from a low friction material.
The diaphragm valve (1) controls the flow rate adjustment according to the difference between Pa (intake
pressure) and Pi (pressure inside the compressor).
N.B. the solution adopted for this compressor is designed to keep the internal pressure Pi constant, with
advantages in terms of ease of adjustment and quiet, smooth operation.
2 Print n° 506.763/23
Marea-Marea Weekend
2000 range ©)
Auxiliary Units
Climate control
50
COMPRESSOR ( 1998 engine)
The compressor fitted on this version is the SANDEN SD6V12 variable capacity type.
The capacity of the compressor varies starting from the maximum value (125.1 cnrfVrev) and is gradually
reduced (up to 6.2 cm /rev) according to the system load variations. - changed outside temperature
and/or humidity conditions or sharp variations in the engine load.
This solution is defined as "unlimited variable capacity".
The compressor is the alternating piston type: the variation in capacity is achieved by tilting the connect
ing rod holder plate with a consequent variation of the piston stroke: the movement of the plate is acti
vated by an internal regulation valve according to the balance of pressure upstream and downstream of
the compressor. In particular a low intake pressure involves the shuttering of the compressor (reduced ca
pacity), whilst a high pressure involves operation at maximum power (maximum capacity).
1. Diaphgram valve
2. Pistons
3. Connecting rods
4. Connecting rod plate
5. Shaft
6. Pin
7. Arm
8. Slide
9. Guide
Operation
The operation is the same as described for the previous SANDEN 7V16 compressor.
Copyright by Fiat Auto 3
Auxiliary Units
Climate control
50
SPECIFICATIONS
TABLE SHOWING QUANTITIES OF OIL AND GAS FOR CLIMATE CONTROL SYSTEM
The table below summarizes the types of oil and the quantities of oil and coolant.
ENGINE TYPE COMPRESSOR TYPE OF
OIL
QUANTITY
OF OIL (cm3)
QUANTITY
OF GAS (g)
1596 16V HR V5 UNICON RL
488 265 600 ± 25
1998 20V SD6V12 SP10 135 600 ± 25
1910 JTD SD 7V16 SP10 135 600 ± 25
FOR ANYTHNING NOT DEALT WITH,
REFER TO THE BASIC MANUAL, ASSEMBLY 50.
Marea-Marea Weekend
2000 range ©
4 Print n' 506.763/23
Marea-Marea Weekend Electrical system
2000 range @ Junction unit
55.
LIST OF FUSES AND MAJOR PROTECTED CIRCUITS
Fuse
No. Amp Symbol Protected circuit Fuse
No. Amp Symbol Protected circuit
1 ion SERVIZI SERVICES
Brake light - Supple
mentary brake light -
Turn signal - Instrument
power supply
6 10 ID Right main beam
headlamp
7 10 ID
Left main beam
headiamp - main beam
headlamp warning light
Right front side light -
Left rear side light
Right number plate light
- Radio light - Instru
8 20 0*
Radio - Door lock -
Boot light
2 10 3>
Side light warning light -
Cigarette lighter light -
Switch panel light -
9 10 A
Hazard warning lamps -
Instrument power supply
(from January 2001)
Automatic transmission
control light - Carphone
light - heater/air condi
tioner control lighting 10 10 SERVIZI SERVICES
Internal lights (front and
back) - Instrument sup
ply (to December 2000)
- remote control receiver
and alarm control unit
supply - Car phone
power supply - Tester
output power supply
3 10 -;o oi-
left front side light
Right rear side light -Left
11 30 Heated rear windscreen
- Mirror demisting
3 10 -;o oi-number plate light
Mirror control light -12 30 8
Car interior climate con
trol fan motor (air con
ditioned).
lO Right dipped beam
headlamp
13 20 Air conditioner control
unit - horns
4 10 lO Right dipped beam
headlamp
14 20
Windscreen wiper - Rear
windscreen wiper
Windscreen / Rear wind
screen wiper - Headlamp
washer intermittence
5 10 %o
Left dipped beam
headlamp - Headlamp
alignment corrector
Headlamp washers inter-
mittence
15 20 La
Air conditioner control
unit - Car interior cli
mate control fan motor
(heated).
(*) Replaced with 15A if tow-hook installed.
Copyright by Fiat Auto XII 00 - Supersedes previous version 7
Marea- Marea Weekend
2000 range ©
Electrical equipment
Control module
55.
The vehicle is fitted with numerous electronic
control units which have autodiagnostic func
tions.
When these control units are connected to di
agnostic equipment (Examiner or other in
struments) it is possible to read the autodiag
nostic information (parameters, errors) or carry
out active diagnosis.
On the version with EOBD (European On
Board Diagnosis) which conforms to Directive
98/69/CE (EURO 3), there is not an indi
vidual diagnostic socket for each control
unit, but a single.- standardized 16-way
diagnostic socket, on the left hand side of
the dashboard, under the junction unit.
The diagnostic equipment (Examiner or other instruments) is connected to it using a special adaptor
known as "MPX 97". Using this adapator it is possible to select the system the autodiagnosis is going to
be carried out on.
Pin- out View of connector, cable entry side
Pin System
1 ABS
2 N.C.
3 Air Bag
4 Power earth
5 Signal earth
6 N.C.
7 Engine management and FIAT CODE
8 N.C.
9 Climate control
10 N.C.
11 Alarm
12 N.C.
13 N.C.
14 N.C.
15 Automatic transmission.
16 Connector supply
Copyright by Fiat Auto 13