US Patent 10989132 Method and system for fuel injector balancing

Methods and systems are provided for injector correction learned while a direct injector delivers fuel as a group of fuel injections per cylinder event. The correction is learned using a pressure based injector balancing approach while relies on a sensed pressure drop across the group of fuel injections. Errors for individual pulses of the group of injections is learned as a function of inter-injection spacing and individual pulse-width commands.