Accumulator type injector for a fuel injection system

The injector is suitable for a common rail fuel injection system in which the jet needle is pressure controlled when the jet needle (5) is opened. When the control valve (23) is closed, the needle is forcibly closed too, due to the inclusion of a 3/2 path valve (31) in the system. The time of beginning of injection and of the closing of the jet needle can thus be controlled with greater precision.