Fuel Injector
- Discovery & Range Rover
Multiport Sequential Fuel Injection (SFI) system uses one fuel injector per cylinder. Fuel injectors are fitted between pressurized fuel rail and intake manifold. Each injector contains a solenoid controlled by ECM. All 8 fuel injectors are supplied with battery voltage. ECM controls injector operation through ground path for each injector. When injector solenoid is energized, a plunger is attracted off its seat and allows pressurized fuel to spray into the intake manifold. Fuel injector total failure or a leak that causes a rich mixture will cause a misfire in affected cylinder.
- Freelander
A split stream, air assisted fuel injector is installed at each cylinder. Injectors are located in the intake manifold and connected to a common fuel rail assembly. Each injector contains a pintle type needle valve and a solenoid winding. The needle valve is held closed by a return spring. An integral nozzle shroud contains a ported disc, adjacent to the nozzles. "O" rings seal the injector in the fuel rail and the intake manifold. The solenoid winding of each injector receives a 12-volt supply from the ECM relay in engine compartment fusebox. The ECM supplies an ground path to the solenoid winding, which energizes and opens the needle valve. When the needle valve opens, two nozzles direct a spray of atomized fuel onto the back of each intake valve. Air drawn through the shroud and ported disc improves atomization and directional control of fuel. The air is supplied from a dedicated port in the intake duct through a plastic tube and tracts formed in the gasket face of the intake manifold. The ECM calculates open time (duty cycle) of injectors from:
- Engine speed.
- Mass air flow.
- Engine temperature.
- Accelerator pedal position (driver demand).