Method and fuel injection system for fuel supply to a

Abstract

A method and a fuel injection system for supplying fuel to a mixture-compressing internal combustion engine having externally supplied ignition is proposed. The fuel injection system includes metering valves, downstream of which regulating valves are disposed and at one side of which the fuel pressure downstream of the metering valves prevails and on the other side of which the fuel pressure in a control pressure line prevails. The control pressure line communicates with the fuel supply line and is limited by a control throttle and a return-flow throttle; from it, a branch line leads to an electromagnetic supplementary injection valve, by way of which further fuel, in addition to the fuel injected via injection valves, can be injected. The triggering of the supplementary injection valve can be effected by an electronic control unit for injecting fuel during cold starting of the engine or in the presence of a measurement signal characterizing an acceleration of the engine. By means of the triggering of the supplementary injection valve, the pressure in the control pressure line is reduced, as a result of which--because of an increase in the pressure difference at the metering valves--a greater fuel quantity is metered.