Abstract: A method is provided for determining whether an injection parameter correction for fuel quality is required in an internal combustion engine, the engine comprising a plurality of cylinders, each one of the cylinders comprising a combustion chamber into which fuel is injected by an associated fuel injector and within which, in use, combustion events repeatedly occur to define a combustion cycle of the cylinder between successive combustion events. The method comprises observing the speed of the combustion cycles of at least two of the cylinders and analysing the at least two speeds to determine if an injection parameter correction for fuel quality is required. The invention also extends to an injector control unit arranged to determine an injection parameter correction for fuel quality.

Abstract: A method is provided for determining whether an injection parameter correction for fuel quality is required in an internal combustion engine, the engine comprising a plurality of cylinders, each one of the cylinders comprising a combustion chamber into which fuel is injected by an associated fuel injector and within which, in use, combustion events repeatedly occur to define a combustion cycle of the cylinder between successive combustion events. The method comprises observing the speed of the combustion cycles of at least two of the cylinders and analysing the at least two speeds to determine if an injection parameter correction for fuel quality is required. The invention also extends to an injector control unit arranged to determine an injection parameter correction for fuel quality.

Abstract: A system for controlling the operation of a diesel engine of a motor vehicle equipped with means for supplying fuel to the cylinders thereof in accordance with at least one main injection and a delayed injection of fuel as a function of a predetermined desired value for the crank angle interval separating the delayed injection from the main injection, wherein it comprises means for estimating the crank angle interval separating the delayed injection from the main injection in at least one cylinder and means for controlling the supply means capable of slaving this estimated interval to the desired interval value.

Abstract: In the method of diagnosing the operating state of a motor vehicle diesel engine of the invention, the engine includes a pressure acquisition system associated with each cylinder of the engine to acquire the pressure in that cylinder, an engine shaft angle acquisition system adapted to deliver the crankshaft angle of each cylinder, and onboard correction system adapted to correct a predetermined set of malfunctions and drifts of the cylinders and the acquisition systems. The method includes an analysis step of analyzing the operation of each cylinder and the cylinder pressure and engine shaft angle acquisition systems by identifying an operating state of the set comprising that cylinder and those systems based on predetermined characteristics of the signal delivered by the cylinder pressure acquisition system, and a correction step of correcting identified malfunctions and drifts.

Abstract: The invention relates to a method of diagnosing the operating state of a motor vehicle diesel engine (10), the engine (10) comprising a pressure acquisition system (18a, 18b, 18c, 18d) associated with each cylinder (12a, 12b, 12c, 12d) of the engine to acquire the pressure in that cylinder, an engine shaft angle acquisition system (30) adapted to deliver the crankshaft angle of each cylinder, and onboard correction means (34) adapted to correct a predetermined set of malfunctions and drifts of the cylinders and the acquisition systems, which method is characterized in that it comprises: an analysis step (102) of analyzing the operation of each cylinder and the cylinder pressure and engine shaft angle acquisition systems by identifying an operating state of the set comprising that cylinder and those systems as either a nominal operating state or one of a set of predetermined malfunctions and drifts based on predetermined characteristics of the signal delivered by the cylinder pressure acquisition system; an