A fuel-injection device for an internal combustion engine

A fuel-injection device for an internal combustion engine includes a stepped pump piston (29) movable in a cylinder bore (27) and defining therewith a driving chamber (35) and a pump working chamber (55), the latter being limited by an annular front face (53) at the smaller pump piston diameter. The chamber (55) is filled with fuel by being connected to a fuel supply line (21) before the device is actuated. The working chamber (35) which is at least indirectly defined by the larger end face (41) of the stepped piston (29) can be connected by a pressure line (37) containing a 3 port, 2 position valve (39) to a pressure line (13) or to a relief line (17). Opening of the pressure line (13) causes actuation of the piston (29) by the conveyance of a highly pressurised medium, located in a pressure reservoir, into the working chamber (35). A measured quantity of fuel admitted to the working chamber (55) is pumped through outlet openings (51) once the annular fuel (53) closes the supply line (21).