APPARATUS AND METHOD FOR REGULATING AND INJECTING GASEOUS FUEL INTO AN INTERNAL COMBUSTION ENGINE

An apparatus includes a pressure regulator, an in-cylinder fuel injector and a controller programmed to, when fueling with a first gaseous fuel, command the regulator to regulate the pressure of the first gaseous fuel to a first injection pressure; and command the injector to inject within 90 CA° of TDC during a compression stroke an injected quantity of a first gaseous fuel into the combustion chamber at the first injection pressure, and when fueling with a second gaseous fuel, to command the regulator to regulate the pressure of the second gaseous fuel to a second injection pressure; and command the injector to inject within 90 CA° of TDC during the compression stroke an injected quantity of a second injected gaseous fuel.