A flow control system, in particular for a fuel injector for an internal combustion engine, said flow control system comprising: - an inlet port for receiving a fluid having a relatively high pressure, - an outlet for letting out said pressurized fluid, - a return port for returning part of said fluid to a volume having a relatively low pressure, - a 2-way control valve comprising a control valve member, a first seat, a first resilient means configured to force said control valve member towards said seat so as to close said control valve, and a first abutment that limits the lift of said control valve member away from said first seat, characterised in that - a main valve comprising a main valve member, a second seat, a main control chamber, and an outlet chamber in fluid connection with said inlet port, said main valve member being configured to be forced by pressure in said main control chamber towards said second seat so as to close an opening to said outlet, - a shuttle valve comprising a shuttle valve body (9, 47), a shuttle control chamber and a third seat, said shuttle valve body (9, 47) being configured to engage with said third seat so as to close an opening between said inlet port and said main control chamber; - a connection channel configured to connect said shuttle control chamber with said main control chamber, wherein said control valve is configured to close and open a connection between said shuttle control chamber and said return port and is biased towards its closed position by said first resilient means, said shuttle valve is biased closed by a second resilient means, said main valve is configured to open and close a connection between said inlet port and said outlet and is biased closed by said second resilient means, further wherein said shuttle valve is configured such that the pressure in said shuttle control chamber tends to open the shuttle valve whereas the pressure in said main control chamber tends to close the shuttle valve, wherein said main valve is configured such that said pressure in said main control chamber tends to close the main valve whereas a pressure in said outlet chamber tends to open the main valve, wherein said first seat of said control valve is slidably arranged in said shuttle control chamber and wherein an end stop for said first seat is provided such that the pressure in said shuttle control chamber tends to move said first seat towards said end stop, further wherein said first seat, upon its mechanical contact with said valve member, is able to transmit at least a part of the force of said resilient means onto said shuttle valve body in the opening direction of said shuttle valve. - an inlet port for receiving a fluid having a relatively high pressure, - an outlet for letting out said pressurized fluid, - a return port for returning part of said fluid to a volume having a relatively low pressure, - a 2-way control valve comprising a control valve member, a first seat, a first resilient means configured to force said control valve member towards said seat so as to close said control valve, and a first abutment that limits the lift of said control valve member away from said first seat, - a main valve comprising a main valve member, a second seat, a main control chamber, and an outlet chamber in fluid connection with said inlet port, said main valve member being configured to be forced by pressure in said main control chamber towards said second seat so as to close an opening to said outlet, - a shuttle valve comprising a shuttle valve body (9, 47), a shuttle control chamber and a third seat, said shuttle valve body (9, 47) being configured to engage with said third seat so as to close an opening between said inlet port and said main control chamber; - a connection channel configured to connect said shuttle control chamber with said main control chamber,