A fuel injection system for Diesel internal combustion engines, particularly vehicle Diesel engines, is proposed which has a full-load stop dependent on atmospheric pressure. The position of the full-load stop which adapts the injection quantity to the variable ambient air pressure is derived from an air pressure adjusting member and transmitted onto the full-load stop via a transmission member. A locking mechanism, which locks the transmission device in a plurality of positions counter to the force exerted by the full-load stop, is associated with the transmission member. The transmission member has two disks draggably coupled within a predetermined range, one of which disks is actuated by the air pressure adjusting member and the other of which disks cooperates with the full-load stop. The draggable coupling effects an adjustment of the full-load stop, if the full-load stop is relaxed, so that the air pressure adjusting member need exert no more than a small adjusting force.