Fuel injection system

A fuel injection system for compressor-equipped internal combustion engines having injection into an intake tube, in which a flow rate member and an arbitrarily actuatable throttle valve are disposed in sequence downstream of a compressor, the flow rate member being movable counter to a restoring force in accordance with a quantity of air flowing therethrough, and a valve disposed in a fuel supply line having a movable element for metering a fuel quantity corresponding to the quantity of air, characterized in that said restoring force is generated by means of pressure fluid, which is exerted continuously upon a control slide under a constant but arbitrarily variable pressure supplied by a control pressure line, said restoring force, and the variation of the pressure of the pressure fluid being effected by means of at least one pressure control valve controllable in accordance with engine characteristics, further wherein said pressure control valve includes a movable valve element upon which a compression spring acts in the closing direction of the pressure control valve, the force of said spring exerted upon the movable valve element being capable of reduction with increasing intake tube pressure downstream of said compressor.