A flow control system for a fuel injector of an internal combustion engine, comprising: - an inlet channel for receiving a pressurized fuel, - an outlet channel for letting out the pressurized fuel, - a return channel for returning part of the pressurized fuel to a low-pressure system having a lower pressure than the pressurized fuel in the inlet channel when in use, - a fuel outlet chamber for receiving the pressurized fluid from the inlet channel, - a nozzle control member arranged in the fuel outlet chamber and configured to be moveable for selectively allowing the pressurized fuel to flow into the outlet channel, - a biasing member biasing the nozzle control member towards a closed position in which the pressurized fuel is prevented from being allowed into the outlet channel, - a moveable member, whereby at least the moveable member and the nozzle control member define a fuel control chamber, the fuel control chamber being configured such that a pressure therein biases the nozzle control member towards its closed position, - a valve member configured to be moveable for selectively opening and closing a flow passage between the fuel control chamber and the return channel, wherein the moveable member is configured to be moveable towards and away from the nozzle control member and to raise pressure in the fuel control chamber when moved towards the nozzle control member, and wherein the valve member is biased towards the moveable member for closing the flow passage and for moving the moveable member towards the nozzle control member, wherein the flow control system further comprises a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber. - an inlet channel for receiving a pressurized fuel, - an outlet channel for letting out the pressurized fuel, - a return channel for returning part of the pressurized fuel to a low-pressure system having a lower pressure than the pressurized fuel in the inlet channel when in use, - a fuel outlet chamber for receiving the pressurized fluid from the inlet channel, - a nozzle control member arranged in the fuel outlet chamber and configured to be moveable for selectively allowing the pressurized fuel to flow into the outlet channel, - a biasing member biasing the nozzle control member towards a closed position in which the pressurized fuel is prevented from being allowed into the outlet channel, - a moveable member, whereby at least the moveable member and the nozzle control member define a fuel control chamber, the fuel control chamber being configured such that a pressure therein biases the nozzle control member towards its closed position, - a valve member configured to be moveable for selectively opening and closing a flow passage between the fuel control chamber and the return channel, wherein the moveable member is configured to be moveable towards and away from the nozzle control member and to raise pressure in the fuel control chamber when moved towards the nozzle control member, and wherein the valve member is biased towards the moveable member for closing the flow passage and for moving the moveable member towards the nozzle control member, wherein the flow control system further comprises a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.