Abstract: An accumulator type injection valve of simple construction and relatively large accumulator capacity has opposed inlet and outlet valves for alternately and intermittently communicating a single chamber with an inlet passage for receiving fuel from a pump and an outlet passage in further communication with an injection nozzle, the outlet valve being an inwardly opening needle valve responsive to fluid pressure within the chamber. In order to even further improve operating response of the injection valve, a dump valve relieves fluid pressure from the chamber below a preselected pressure.