Internal combustion engine, control system and operating method for determining a fuel attribute

Abstract

A method of operating a fuel injected multi-cylinder internal combustion engine includes electronically storing a first value or reference value indicative of an engine speed response to a commanded fueling duration change during fueling the engine with a first fuel or reference fuel, such as a known type of diesel fuel. The method further includes operating the internal combustion engine in a fuel testing mode during fueling with a second fuel or test fuel, such as an unknown type of diesel fuel. The fuel testing mode includes determining a second value or test value indicative of an engine speed response to a commanded fueling duration change, comparing the test value with the reference value and outputting a fuel attribute signal which is based at least in part on comparing the reference value and the test value. If a difference between the reference value and the test value satisfies corrective action criteria, a corrective action such as adapting fuel injector control signal duration or shutting down the engine can be taken. An engine and control system whereby the operating method is executed are also provided.