Injection pump (1208)
Role
The injection pump provides 3 functions
- Pumping
- Timing
- Metering
Description
The injection pump consists of various control elements
- Advance solenoid valve
- Fuel cut-off solenoid valve
- Potentiometer (load lever sensor)
The injection pump operates as follows
- A piston (2) situated in the housing is connected by a swivel joint (3) to the camshaft ring (5)
- A return spring (4) allows the piston (2) to move when it is not subjected to the transfer pressure
- The pressure operating the piston is modified by a leak off controlled by a solenoid valve (1) fitted through the housing in the hydraulic head
- This solenoid valve is controlled by a signal from the LUCAS DCN2 ECU
Special features
See
- Throttle potentiometer
- Advance solenoid valve
- Coded anti-start
Installation
The injection pump is positioned at the front of the engine
Control unit (1320)
Role
Using the data which it receives from the various sensors, the ECU carries out the following functions
- Advance check
- EGR check
- Air conditioning cut-off check
- Pre-heat check
- Fast idle control
Description
The ECU is fitted with modular connectors (only 2 connectors are used)
- 1 connector 48V.MR
- 1 connector 48V.NR
Special features
The ECU can be downloaded
The air conditioning parameter can be switched on or off in a standard automatic manner (vehicle without air conditioning)
Installation
The ECU is located in the top left area of the engine compartment
Multifunction double relay (1304)
Role
The multifunction double relay supplies the following functions
- Immobiliser control unit
- EGR electrovalve
- Advance solenoid valve
- Control unit
Description
As soon as the ignition is switched on the two relays are energised
The first relay supplies
- Control unit
- EGR electrovalve
- Advance solenoid valve
The second relay supplies: immobiliser control unit
When the ignition is switched off the built-in systems interface re-supplies the double multifunction relay
The purpose of this operation is to supply the (8208) electronic unit in order to lock the stop solenoid supply
Installation
The multifunction double relay is installed in the engine compartment under the injection ECU
Engine speed sensor
Role
The engine speed sensor supplies a signal to the ECU giving the rotation speed of the engine
The engine speed sensor defines the position of the crankshaft by means of two diametrically opposite slots on the engine flywheel
Description
Us: output voltage
T: time
A: passing in front of a slot
B: 1 engine revolution(s)
The sensor is of the inductor type
Composition of the sensor
- 1 if the difference in potential is greater than V, the electric cables (cable + alternator, battery cable) must be replaced
- 1 electric coils
When the slots of the engine flywheel pass in front of the sensor a variation in the magnetic field is created which induces alternating voltage in the coils (sine-wave signal)
The frequency and amplitude of this voltage are proportional to the rotational speed of the engine
Special features
Assignment of the connector terminals
- Terminal 1: signal (+)
- Terminal 2: signal (-)
Installation
The magnetic speed sensor is located at the top of the clutch housing
The position of the interconnection on the cooling circuit does not change
NoteThe air gap value is non-adjustable
Vehicle speed sensor (1620)
Role
This sensor transmits data to the ECU (8 times per revolution, minimum speed 2 km/h) enabling the gear engaged to be determined, using the engine speed
This data is used with the aim of improving the driveability of the vehicle
Description
This type of Hall effect sensor is supplied with 12 V
Special features
Assignment of the 3V.BA connector terminals
- Terminal 1: +ve CC (ignition controlled positive)
- Terminal 2: earth
- Terminal 3: signal
Installation
The vehicle speed sensor is located at the gearbox outlet
Injector needle lift sensor (1260)
Role
The needle lift sensor informs the ECU of the start of the fuel discharge
This information is used for dynamic correction of the advance
Description
The injector needle is extended by a stem (1) through the spring (2)
The sensor is supplied by a constant amperage
When the injector opens, the core (3), which is part of the stem, moves in the sensor, changing the inductance of the coil (4)
The ECU is thus informed of the opening of the injector
Special features
Assignment of the 2V.NR connector terminals
- Terminal 1: map reading lamp
- Terminal 2: signal
Installation
The needle lift sensor is located under no. 1 injector
The connector of the needle lift sensor is sited on the engine oil guide bracket
Engine coolant temperature sensor (1220)
Role
The role of the sensor is to inform the ECU of the heat status of the engine by measuring the temperature of the coolant
Description
The thermistor is of the NTC (Negative Temperature Coefficient) type located in the cooling system
The sensor is fitted with a third terminal which transmits a coolant temperature signal to inform the driver
Special features
Assignment of the 3V.BE connector terminals
- Terminal 1: supply +5 V
- Terminal 2: signal
- Terminal 3: temperature display
Installation
A single sensor is located at the front of the water outlet housing
Fuel cut-off solenoid valve (1255)
Role
The solenoid valve authorises the flow of diesel to the injection hydraulic head
Description
When the ignition is switched on, if the key is recognised, the built-in systems interface unlocks the (2) CAS electronic unit which allows supply of the stop solenoid (1): the vehicle is able to start
When the ignition is switched off the stop solenoid (1) is no longer supplied; after a timed delay the control module sends the request for locking for the (2) CAS electronic unit in order to prevent supply to the stop solenoid (1)
Special features
Assignment of the terminals of connector 4V.NR in the CAS electronic unit
- Terminal 1: +ve CC (ignition controlled positive)
- Terminal 2: not connected
- Terminal 3: CAS communication
- Terminal 4: engine earth
Installation
The (2) CAS electronic unit is located on the stop solenoid (1) which is on the distribution head of the injection pump
NoteTo access the stop solenoid it is necessary to remove the CAS electronic unit
Atmospheric pressure sensor
Role
The sensor measures the atmospheric pressure
The role of the injection ECU in terms of the information received: to prevent recirculation when driving at a high altitude
NoteThe density of the air decreases according to the altitude
Description
1: control unit
2: atmospheric pressure sensor
The sensor is of the piezo-electric type
The sensor consists of strain gauges
The sensor supplies a voltage proportionate to the atmospheric pressure
Installation
The atmospheric pressure sensor (2) is incorporated in the injection ECU
NoteThe atmospheric pressure sensor cannot be separated from the injection ECU
Engine diagnosis warning lamp (V1300)
Role
The diagnostic warning light warns the driver if a fault detected by the injection ECU appears
Description
The warning light, supplied with +12 V, is controlled by the injection ECU by means of an earth
- A: normal operation or minor fault
- B: major fault
When the ignition is switched on, the warning lamp remains lit until the engine starts
When the engine is running, the light comes on every time a major fault is detected, and remains lit as long as the fault has not disappeared
NoteAfter switching on 40 times, if the fault does not re-appear, it is cleared
Installation
Diagnostic warning light on the instrument panel