Patent attributes
Apparatus and method for testing fuel flow in a return or returnless fuel system. The apparatus comprises a primary flow passage having an inlet for connection to the fuel system for receiving fuel pumped by the fuel pump, and an outlet adapted for connection to the fuel system for flow of fuel to one or more fuel injectors. The apparatus includes a first device for measuring a rate of fuel flow through the primary flow passage, and a second device for measuring a fuel pressure in the primary flow passage. A bypass valve in the primary flow passage is movable between a first position in which the bypass passage is closed and a second position in which the bypass passage is open. The bypass valve is movable to its first position for testing fuel flow in a return flow system and to its second position for testing fuel flow in a returnless fuel flow system. Different embodiments of the apparatus and methods of using the apparatus are disclosed.