GF07.61-P-3004AMG ME Fuel Supply, Function

GF07.61-P-3004AMG ME Fuel Supply, Function







The fuel supply makes available filtered fuel in sufficient quantities and a sufficient pressure (injection pressure) under all operating conditions to the fuel injection valves.

Fuel supply is controlled and monitored by the ME-SFI [ME] control unit and the fuel pump control unit(s).

The fuel pressure is regulated variably according to fuel requirements from 4.0 to 5.5 bar (for model 216, 221 from 4.6 to 5.5 bar). One or two fuel pump(s) matched to the engine is or are integrated into the fuel tank.

Switching on of fuel pump(s) takes place via a discrete signal (signal with a specific voltage value) from the ME-SFI [ME] control unit at the fuel pump control unit(s).

In order to control the fuel pumps, the ME-SFI [ME] control unit detects the current fuel pressure via the fuel pressure sensor and sends a PWM signal (pulse width modulated signal) signal representing the current fuel requirements to the fuel pump control unit.

Each fuel pump control unit evaluates the PWM signal and actuates the fuel pump it is connected to accordingly.

The fuel pump(s) draw(s) the fuel below out of the fuel tank and deliver(s) it through the fuel filter with pressure limiting valve to the fuel injection valve on the fuel distribution rail (single-line system). The fuel pressure is limited in the process by the pressure limiting valve to a max. of 6.0 bar (for model 216, 221 to a max. of 6.5 bar). A junction in the fuel line upstream of the fuel filter provides the suction jet pump in the left fuel tank chamber with part of the flow the fuel feed. The suction jet pump delivers the fuel out of the left fuel tank chamber into the fuel feed module (right fuel tank chamber).

For model 164 and 251 a suction jet pump also fills the fuel feed module in the right fuel tank chamber. This suction jet pump is driven by a part of the flow of the fuel feed from the left fuel pump.

The fuel pump(a) is/are installed in a fuel feed module. The housing of the fuel delivery module serves as a swirl pot. The swirl pot prevents the fuel pump(s) from drawing air while cornering with a low level of fuel in the fuel tank.