The present disclosure is directed to various embodiments of systems and methods for reducing the production of harmful emissions in combustion engines. One method includes correlating combustion chamber temperature to acceleration of a power train component, such as a crankshaft. Once the relationship between acceleration/deceleration of the component and combustion temperature are known, an engine control module can be configured to adjust combustion parameters to reduce combustion temperature when acceleration data indicates peak combustion temperature is approaching a harmful level, such as a level conducive to the formation of undesirable oxides of nitrogen. Various embodiments of the methods and systems disclosed herein can employ injectors with integrated igniters providing efficient injection, ignition, and complete combustion of various types of fuels.