Pressure washer engine idle controller

An engine idle controller adapted to be connected in a pressurized liquid delivery path of a pressure washer between an engine driven pump and a wand having a liquid flow control valve and a spray nozzle, said engine idle controller including a housing defining a cylinder and a rod passage extending from said cylinder through said housing, a piston positioned in said cylinder, a rod having a first end connected to said piston and having a second end extending through said rod passage and projecting exterior to said housing, said piston and rod being mounted to slide in said housing between first and second positions, said piston dividing said cylinder into first and second chambers, said projecting rod second end being adapted to be connected to move an engine throttle on a pressure washer between an idle setting when in said first position and full throttle settings when in said second position, said engine idle controller having an inlet adapted to receive pressurized liquid from the pump, an outlet adapted to be connected to the wand, a flow restriction located between said inlet and said outlet and being adapted to create on an outlet side of said flow restriction a reduced pressure in pressurized liquid flowing between said inlet and said outlet and substantially the inlet liquid pressure when liquid does not flow between said inlet and said outlet, wherein the pressure at said inlet is applied to said first chamber and wherein the pressure at said outlet side of said flow restriction is applied to said second chamber.