The present disclosure is directed to integrated injector/igniters providing efficient injection, ignition, and complete combustion of various types of fuels. One such injector/igniter can include a body having a base portion opposite a nozzle portion. The base portion receives fuel into the body and the nozzle portion can be positioned adjacent the combustion chamber. The injector further includes a valve carried by the nozzle portion that is movable between a closed position and an open position to inject the fuel into the combustion chamber. An actuator is coupled to the valve and extends longitudinally through the body towards the base portion, and a driver is carried by the body and is movable between a first position and a second position. In the first position the driver does not move the actuator and in the second position the driver moves the actuator to move the valve to the open position.