Fuel injection system for a multicylinder internal combustion engine

A common rail fuel injection system for a multi-cylinder internal combustion engine with magnetic valve-controlled direct-injection fuel injectors, each comprising an injector housing including an injection nozzle with a spring-loaded nozzle needle, a control piston with a valve structure formed at one end thereof for controlling high pressure fuel admission from a high pressure fuel supply to a fuel supply passage extending through said housing to said injection nozzle, a nozzle needle closing spring being disposed in a spring chamber and engaging said nozzle needle to resiliently hold said nozzle needle seated on a needle seat, said control piston having its other end exposed to the fuel pressure in a control chamber, which is in communication with said high pressure fuel supply by way of a throttle structure, a magnetic valve arranged adjacent said control chamber for controlling a communication path to a drain line for releasing pressurized full from said control chamber in order to establish communication between said high pressure fuel supply and said fuel supply passage for the ejection of fuel through said injection nozzle, said spring chamber being in communication with said fuel supply passage by a communication passage including a throttle structure permitting limited fuel flow to said spring chamber such that, upon failure of said injector resulting in a continuous pressurization of said fuel supply passage, the pressure in said spring chamber builds up to seat the nozzle needle thereby interrupting fuel ejection from said injector.