A valve actuator assembly for an engine includes a movable engine valve, a movable first spool valve, and a movable second spool valve. The valve actuator assembly also includes an intermediate channel interconnecting the first spool valve and the second spool valve, and a driving channel, a first feedback channel, and a second feedback channel interconnecting the second spool valve and the engine valve. The valve actuator assembly includes an actuator operatively cooperating with the first spool valve to position the first spool valve to prevent and allow high pressure fluid flow to the second spool valve and the driving channel to position the engine valve. The valve actuator assembly further includes a first on/off valve and a second on/off valve in fluid communication with the first feedback channel and the second feedback channel to enable and disable the first feedback channel and the second feedback channel, whereby the first on/off valve and the second on/off valve control motion of the second spool valve.