Patent ID: 7181333

Claim:
A method for determining the phase of a crankshaft of an internal combustion engine, said internal combustion engine comprising a plurality of cylinders whose firing sequence occurs over two revolutions of said crankshaft with a first set of cylinders whose power stroke occurs during a revolution of said crankshaft and a second set of cylinders whose power stroke occurs during a different revolution of said crankshaft, each cylinder configured to possess an injection window in which fuel is allowed to be injected, said method comprising: generating a command signal to inject fuel into at least one cylinder from said first set of cylinders during an injection window; generating a command signal to inject fuel into at least one cylinder said first set of cylinders at a time out of phase with said injection window; monitoring an indicator of engine performance that is responsive to firing and non-firing of said cylinders; and deducing correct engine phase based on fluctuations in said engine indicator corresponding to said generating of fuel injection command signals during an injection window and said generating of fuel injection command signals out of phase with said injection window.