Abstract: There is described a method of controlling the combustion of a direct-injection diesel engine having a common-rail injection system. The control method includes the steps of performing, at each engine cycle and in each cylinder of the engine, a first main fuel injection around the end-of-compression top dead center position, and at least one of a first auxiliary fuel injection preceding the first main injection, and a second auxiliary fuel injection following the first main injection. More specifically, the two auxiliary injections are performed close enough to the first main injection to take part, together with the first main injection, in the actual combustion of the fuel, so as to reduce the pollutant substances present in the exhaust gases, and the combustion noise produced by the engine.

Abstract: A method and apparatus of controlling supercharge pressure following rapid acceleration includes the steps of generating a pressure signal related to the value of the supercharge pressure of an engine; generating a reference signal related to a desired supercharge pressure value; generating a correction signal related to a time derivative of the pressure signal; generating an acceleration output signal as a function of a linear combination of the pressure signal, the reference signal and the correction signal; and supplying the acceleration output signal as a control signal.

Abstract: The diagnostic method includes the steps of generating an acceleration signal related to the intensity of vibration in an engine; comparing the amplitude of the acceleration signal with a predetermined reference amplitude value; generating a fault indicator when the amplitude of the acceleration signal exceeds the predetermined reference amplitude value; determining a crossover drive angle value upon the amplitude of the acceleration signal exceeding the predetermined reference amplitude value; comparing the crossover drive angle value with a predetermined reference angle value; and generating a fault signal in the event the crossover drive angle value is less than the predetermined reference angle value.

Abstract: The structure has a number of sleeves fitted about the conduits of a supply circuit supplying fuel to the injectors of an engine. Each sleeve is tubular, and has a bellows type main body, two opposite end portions, and an outlet fitting extending from one of the end portions. The sleeves are fitted to the conduits by fitting the end portions in fluidtight manner to fittings at opposite ends of the conduits. The outlet fitting of each sleeve is then connected to a catch header by a respective connecting line, which connects the inner cavity of the main body to the catch header to enable any fuel leakage from the conduits to flow into the catch header.

Abstract: The method includes the steps of generating a reference injection pressure value as a function of the speed of a diesel engine and of the quantity of fuel supplied to the engine, the reference injection pressure value defining an optimum injection pressure value for steady-state operation of the engine; generating an incremental injection pressure value as a function of the speed of the engine and the supercharge pressure of the engine, the incremental injection pressure value defining the maximum permissible variation in injection pressure between one engine cycle and the next during a transient operating state of the engine; and generating a desired injection pressure value as a function of the reference injection pressure value and the incremental injection pressure value, and such that the variation in injection pressure during the transient operating state of the engine does not exceed the maximum permissible value.

Abstract: The diagnostic method includes the steps of: generating a pressure signal related to the fuel pressure of an injection system of an engine; comparing the pressure signal with a reference pressure value; determining a fuel leakage condition of the injection system when the pressure signal is less than the reference pressure value; reducing the quantity of fuel injected into the cylinders of the engine in the presence of the leakage condition; calculating a share value contributed by each cylinder to the work torque value generated by the engine; comparing each share value with a respective reference share value; determining a jammed-open injector condition when at least one of the share values is greater than the respective reference share value; and determining a supply circuit failure condition when the share values are all less than the respective reference share values.