Fuel Injectors
| ITEM | DESCRIPTION |
|---|---|
| 1 | Fuel return |
| 2 | O-ring seal |
| 3 | Piezo stack actuator |
| 4 | Hydraulic coupler |
| 5 | Control valve |
| 6 | Nozzle body |
| 7 | Copper sealing washer |
| 8 | Electrical connector |
| 9 | High Pressure (HP) feed |
| 10 | Nozzle |
Six fuel injectors are used in the fuel system. A piezo actuator in each injector is electronically controlled by the Powertrain Control Module (PCM) to operate the injector in response to engine speed and load conditions.
Each injector has an electrical connector which connects the injector to the engine harness. A fuel connection on the top of the injector provides for the HP fuel inlet from the related fuel rail. A second fuel connection allows fuel leakage within the injector to drain into the LP fuel return line.
Each injector is located in a machined hole in the cylinder head and is sealed in the cylinder head with a copper sealing washer and an O-ring seal. The injector is retained in the cylinder head with a clamp plate and two bolts. If an injector is removed or replaced, a new copper sealing washer and a clamp plate must be used when refitting the injector.
The injector can operate up to five times during one combustion cycle depending on engine speed and load.
The injection sequence can occur as follows:
- Pilot injection - occurs before the main injection and improves fuel and air mixing.
- Pre-injection - shortens the main injection's ignition delay and therefore reduces the generation of nitrous oxides.
- Main injection - delivers the required engine torque.
- After injection - occurs after the main injection and assists the re-burn of any remaining particulate matter.
- Post injection - helps manage the temperature of the exhaust gas for more effective exhaust-gas after-treatment.
- Injection delay 0.4 ms.
Each injector is calibrated to the PCM and applicable cylinder to which it is fitted. Therefore, if an injector is removed it must be refitted to the cylinder from which it was removed. If a new injector is fitted, a calibration routine must be performed to calibrate the injector unique code to the PCM, using Land Rover approved diagnostic equipment.
The operating voltage of the injector is between 110 and 163 V depending on engine speed and load and care must be taken when working in the vicinity of the injectors. The pressure increases linearly from 200 to 1200 bar (2900 to 17404 lbf/in2 ).
Each injector has an electrical resistance value of between 150 - 250 kOhm.