US Patent 7546835 Fuel delivery system for multi-fuel engine

A fuel delivery system for an internal combustion engine and a method of operating the fuel delivery system are provided. An example embodiment of the method includes: transferring at least some fuel from a first fuel storage region to a second fuel storage region via a pump during a first condition; draining at least some fuel from the second fuel storage region to the first storage fuel region via gravity during a second condition; and delivering fuel from the first fuel storage region to a first fuel injector of a cylinder of the internal combustion engine; and delivering fuel from the second fuel storage region to a second fuel injector of the cylinder.