An engine valve actuation system includes an engine valve moveable between first
and second positions, a valve actuation assembly connected to move the engine valve
between the first and second positions, a fluid actuator configured to selectively
modify a timing of the engine valve in moving from the second to the first position,
a source of fluid, and a pair of passages in the cylinder that allow fluid to flow
from the chamber to the fluid source. The fluid actuator includes a cylinder and
a piston at least partly defining a chamber. The piston is slidably movable in
the cylinder between a first position and a second position, and blocks at least
a portion of one of the passages at an intermediate position between the second
position and the first position to reduce fluid flow from the chamber when the
piston moves from the second position toward the first position.