actuation fluid may be used such as fuel in operation with the area under piston 48 vented spring 22 and actuation fluid pressure above piston 48 will hold the needle closed even against intensified fuel pressure in the needle chamber when injection is to occur needle control valve 40 is actuated to couple actuation fluid pressure to the region below piston 48 which pressure balances the piston allowing intensified fuel pressure in the needle chamber to force the needle open against spring 22 of course at the end of injection the needle control valve 40 is released to again vent the area under piston 48 to allow actuation fluid pressure over piston 48 to force the needle closed of course the needle control valve 46 may be operated more than once first to provide a pre injection followed by a second injection or even to provided pulsed injections of particular importance to the present invention are the large storage volumes 50 also shown in the cross section of fig2 the generous porting 52 and the ball check valve 54 this is contrary to the prior art where this would be considered energy wasting volume because of its constant pressurization and depressurization in the present invention the storage of fuel at the intensified pressure is facilitated by check valve 54 which prevents depressurization of the intensified fuel pressure when the intensifier is recycled instead injection is controlled by the needle control valve 40 thus the pressurized actuation fluid may be left acting on intensifier piston 26 until recycling the intensifier.