Method and device for determining the pressure in the combustion chamber of an internal combustion engine, in particular a spontaneous ignition engine, for controlling fuel injection in the engine

A method is described for controlling fuel injection in an spontaneous ignition engine (1) equipped with an electronically controlled fuel injection system (2) and with an electronic control unit (4) receiving engine quantities comprising the pressure (P) in the combustion changer of the engine (1) and closed-loop controlling the fuel injection system (2) on the basis of the pressure (P) in the combustion chamber, in which the pressure (P) in the combustion chamber is determined as a function of engine kinematic quantities such as the engine speed and the crank angle (rpm, &thetas;) and of the fuel injection law, which is defined by the quantity of fuel injected (mc) and by the crank angle at the start of injection (SOI).