An engine idle controller for an engine driven pressure washer. The
pressure washer delivers high pressure water from a pump through the idle
controller to a conventional wand which includes a manually operated,
normally closed flow control valve and a spray nozzle. When the wand valve
is opened, a resulting pressure drop between two chambers in the flow
controller acts on a piston to move the engine throttle to a full throttle
position. When the wand valve is closed, the pressures in the chambers
equalize and the piston is moved to a position to set the engine throttle
to an idle position.
