Abstract: A method of commissioning an internal combustion engine controlled by an electronic engine control unit (ECU) is described. The method of commissioning includes an engine mapping function in which the engine is mapped at a combination of speeds and loads to build up a full set of engine operating parameters which are known collectively as the engine control set (ECS). The method includes defining a speed/load mapping table and generating a graphical display of a corresponding speed/load grid (20) having a plurality of cells arranged in a grid, each cell corresponding to a particular speed/load combination in the speed/load mapping table. The engine is driven as close as possible to a selected speed/load combination (24) and the value of a selected engine operating parameter is adjusted to obtain an optimum value at the selected speed/load combination. Each unmapped cell in the grid is displayed in a first visually distinct manner and each mapped cell is displayed in a second visually distinct manner.

Abstract: An engine control unit and method of controlling the operation of a gas fuelled internal combustion engine of the kind having a gas injector for injecting gaseous fuel into each cylinder and an inlet manifold through which air flows into each cylinder of the engine, the inlet manifold having a manifold valve to control the flow of air into the inlet manifold. An improved control strategy employed by the engine control unit involves closed loop control of airflow through the inlet manifold of the engine. Manifold absolute pressure (MAP) (70) and manifold air temperature (MAT) (72) are employed to calculate air density (84) which is representative of the mass of air flowing through the inlet manifold (28). The detected air density (84) is compared to a desired air density (DAD) (86) and an air density correction (88) is calculated to adjust the manifold valve position (MVP) (90).