Patent ID: 7203592

Claim:
A method for detecting misfires of a mixture between a fuel and an oxidizing agent, in any one of the cylinders of an internal combustion engine, this method being characterized in that it comprises the following steps: a) during at least some of the phases of combustion in at least one of the cylinders, a current value, at an instant (t) of operation of the engine, of an index I(t) representative of operational irregularities in the engine stroke is calculated, b) while the engine is operating, and on the basis of the current value, at the instant (t) of the index I(t), the current value at the same instant (t) of an observation function E(t) is calculated, such that: E ( t )= I ( t )− Ī ( t±Δt ) where Ī(t±Δt) is an estimated value of the index I(t) at an instant (t±Δt) different from (t), c) the current value of E(t) is compared with a predetermined threshold (S) dependent on the engine load (C) and/or speed (N), and d) a misfire is diagnosed when the value of E(t) exceeds the threshold (S) the index I(t) being calculated from a linear combination of at least two elemental indices (I 1 , I 2 , I 3 ) each representative of operational irregularities of the engine in a predetermined engine operating domain (ΔC, ΔN), the elemental indices (I 1 , I 2 , I 3 ) being weighted, in the combination, with predetermined relevance coefficients (α, β, γ) obtained in more or less identical operating conditions on a bench-tested reference engine.