Fuel supply system

A fuel supply system for mixture-compressing, externally ignited internal combustion engines having an air intake conduit, in which an air flow rate meter and an arbitrarily actuatable throttle valve are disposed in sequence and the air flow rate meter is moved against a restoring force in accordance with the quantity of air passing therethrough to thereby adjust the movable part of a valve disposed in the fuel supply line for the apportionment of a quantity of fuel proportional to the quantity of air and in which said restoring force is generated by means of pressure fluid which being under substantially constant pressure continuously acts upon a control element operatively connected with the air flow rate meter to effect the restoring force with said pressure fluid being controllable by means of at least one pressure control valve, further wherein each said control element and said pressure control valve includes an air chamber separated from a fuel chamber by a yielding member with each said fuel chamber being subjected to the same fuel pressure upstream of said fuel apportionment valve and each said air chamber subjected to the same pressure in the air intake line upstream of the air flow rate meter.