ME Fuel Supply Function

ME Fuel Supply Function

ENGINE 111.951 /955, 112.912 /916 /946 /953 in MODEL 203
ENGINE 112.913 /917 /949 /954, 113.967 /969 in MODEL 211
ENGINE 112.912 /955, 113.968 in MODEL 209




Shown in Model 203
17 Fuel rail
51 Pressure gauge connection
55/1 Fuel filter with integrated diaphragm pressure regulator
75 Fuel tank
77 Activated charcoal canister
88 Fuel delivery module
92 Fuel pressure line to engine
Y58/1 Purge control valve
Y62 Injectors (LH-SFI, HFM-SFI, PEC [LH, HFM, PMS])




Shown in Model 203
48 Fuel pressure regulator vent line
55/1 Fuel filter with integrated fuel pressure regulator
89/1 Left closing plate
B4/3 Fuel tank pressure sensor (USA)
A Fuel pressure line to engine (controlled fuel pressure)

The fuel supply system must make available to the fuel injectors an adequate quantity of filtered fuel from the fuel tank, and at an adequate pressure (injection pressure), in all operating conditions.

Function
The fuel pump in the delivery module (88) draws the fuel out of the right chamber in the fuel tank (75) and pumps it through the fuel filter with integrated diaphragm pressure regulator (55/1) to the injectors connected to the rail (17) (single-line system).
The fuel in the left chamber is pumped along a connecting line with a suction spray pump to the right chamber.

The diaphragm pressure regulator regulates the fuel pressure to approx. 3.7 to 4.1 bar The fuel pressure is controlled independently of the intake manifold pressure. When the throttle is depressed sharply, fuel supply is assured by means of the acceleration enrichment. The large-volume fuel rail prevents the formation of vapor bubbles.

Too much delivered fuel flows from diaphragm pressure regulator back into the fuel tank (75).
The ventilation of the diaphragm pressure regulator in the fuel filter is performed on Model 203, 209 through a hose line (48). On Model 211, the fuel filter and diaphragm pressure regulator are mounted in the fuel tank.

The fuel injectors operated by the ME-SFI control unit, inject the fuel as a finely atomized spray into the intake passage.