Caterpillar Inc.
Method and system for monitoring injector valves

Abstract:

A method for controlling a fuel injector includes applying a spill valve current, applying a control valve current, the control and spill valves including components in electrical communication with each other, and detecting a timing at which the spill valve returns to an open position based on induced spill valve current. The method includes detecting a timing at which the control valve returns to a resting position based on induced control valve current, the induced spill valve current and the induced control valve current being included in respective freewheeling currents that at least partially overlap each other, adjusting a spill valve current that is applied during an injection, based on the detected spill valve return timing, and adjusting a control valve current that is applied during the injection, based on the detected control valve return timing.