Fuel Supply and Management

Fuel Supply and Management

High-precision Injection (HPI)
The fuel is delivered from the fuel tank by the electric fuel pump via the feed line at an admission pressure of 5 bar to the high pressure pump.

The admission pressure is monitored by the low pressure sensor. The fuel is delivered by the electric fuel pump in line with demand. If this sensor fails, the electric fuel pump continues to run at 100% delivery with terminal 15 ON.

The fuel is compressed in the permanently driven single-piston high pressure pump and delivered through the high pressure line to the rail.

The fuel accumulated under pressure in the rail in this way is distributed via the high pressure lines to the piezo-injectors.

The required fuel delivery pressure is determined by the enginemanagement system as a function of engine load and engine speed. The pressure level reached is recorded by the rail pressure sensor and communicated to the engine control unit.

Control takes place by means of the volume control valve based on setpoint/actual value adjustment of the rail pressure.

Configuration of the pressure is geared towards best possible consumption and smooth running of the N63 engine. 200 bar is required only at high load and low engine speed.