Abstract: A method is provided for operating an internal combustion engine comprising a combustion chamber defined by the inner wall of a cylinder, a cylinder head and the upper surface of a piston moveable longitudinally within the cylinder, the engine further comprising a pre-combustion chamber in communication with the combustion chamber. The method comprises supplying to the combustion chamber a first combustible mixture of a first hydrocarbon fuel and oxygen; supplying to the pre-combustion chamber a second combustible mixture of a second hydrocarbon fuel and oxygen, the second combustible mixture being auto-ignitable; and compressing the first and second combustible mixtures by moving the piston within the cylinder; wherein under operating conditions in which the aforementioned steps are insufficient to operate the engine and keep it running, the method further comprises the step of generating a spark to cause ignition of the compressed first combustible mixture in the combustion chamber.

Abstract: An air-fuel ratio controller for a gaseous-fueled, turbocharged engine having an air manifold, a gas manifold, and a turbine inlet is disclosed herein. The controller includes means for controlling air manifold pressure and means for controlling turbine inlet temperature. The means for controlling air manifold pressure includes means for providing an air manifold pressure set point signal based on gas manifold pressure and engine RPM's and at least one constant input. The means for controlling turbine inlet temperature includes means for modulating the slope of the set point signal for the air manifold pressure controller.