Abstract: A method for checking the operation of a high-pressure fuel supply unit for an internal combustion engine, consisting in driving a high-pressure fuel injection pump by a starter, and after the engine is synchronised and fuel injection into the cylinders is shut off, in defining an initial base pressure in a high-pressure rail, in activating the injection pump by issuing successive timing and angle-setting commands, on the basis of the initial pressure, and in comparing the first pressure and the second pressure obtained in the rail by these timing and angle-setting commands, and/or by comparing at least one of the pressures with a reference pressure in order to check the operation of the high-pressure fuel supply unit for the internal combustion engine.

Abstract: A method for starting a direct-injection internal combustion engine of a vehicle includes: rotating the high-pressure injection pump by a starter; measuring fuel pressure delivered by the pump, taken at two successive compression top dead centers of the pump operating in maximum output mode; establishing the pressure gradient of the fuel, on an angular reference system, based on the two successive pressure measurements; comparing the established gradient with a predefined bijective table that respectively matches a plurality of quantities of fuel to be injected and a plurality of pressure gradients; and adapting the quantity of fuel injected during the starting phase before the engine reaches steady operating speed, depending on the result of the comparison, in order to inject a quantity of fuel that corresponds, in the predefined bijective table, to the established pressure gradient, upon authorization of the first injection given by the engine control unit.

Abstract: A method for checking the operation of a high-pressure fuel supply unit for an internal combustion engine, consisting in driving a high-pressure fuel injection pump by a starter, and after the engine is synchronised and fuel injection into the cylinders is shut off, in defining an initial base pressure in a high-pressure rail, in activating the injection pump by issuing successive timing and angle-setting commands, on the basis of the initial pressure, and in comparing the first pressure and the second pressure obtained in the rail by these timing and angle-setting commands, and/or by comparing at least one of the pressures with a reference pressure in order to check the operation of the high-pressure fuel supply unit for the internal combustion engine

Abstract: A method for starting a direct-injection internal combustion engine of a vehicle includes: rotating the high-pressure injection pump by a starter; measuring fuel pressure delivered by the pump, taken at two successive compression top dead centers of the pump operating in maximum output mode; establishing the pressure gradient of the fuel, on an angular reference system, based on the two successive pressure measurements; comparing the established gradient with a predefined bijective table that respectively matches a plurality of quantities of fuel to be injected and a plurality of pressure gradients; and adapting the quantity of fuel injected during the starting phase before the engine reaches steady operating speed, depending on the result of the comparison, in order to inject a quantity of fuel that corresponds, in the predefined bijective table, to the established pressure gradient, upon authorization of the first injection given by the engine control unit.