Liquid-cooled in-line fuel pump

摘要

A fuel system for a fuel injected internal combustion engine has a liquid-cooled fuel pump which draws fuel from a liquid-vapor separator and delivers it under pressure to the engine at a rate higher than that necessary to operate the engine. Preferably, a fuel pressure regulator downstream of the fuel pump and adjacent the engine bypasses excess fuel to a return fuel chamber in communication with the liquid-cooled fuel pump to cool the return fuel before it is returned to the liquid-vapor separator. Reducing the temperature of the returned fuel before it is discharged into the liquid-vapor separator reduces the generation of vapor in the liquid-vapor separator thereby enabling use of a smaller, less expensive vapor separator. Reducing the amount of fuel vapor in the system is desirable because the fuel vapor can decrease the efficiency and life of the fuel pump and is environmentally hazardous.