Patent ID: 6305352
Filing Date: 2001-10-23
Classification: G01M

Abstract:
A process for detecting an abnormal perturbation of a torque of an internal combustion engine and suspending an operation of a system for diagnosis of misfires, which system operates by analysis of values of a variable representative of firing quality by observation of rotation of an engine crankshaft, said process comprising the steps of:defining a criterion of stability of said variable for each cylinder of the engine and for each firing;comparing, after each firing, the stability criterion with a predetermined threshold; anddetecting an abnormal torque perturbation when said stability criterion exceeds, for at least one cylinder, the threshold for a given number of consecutive times,wherein said stability criterion quantifies, for a given cylinder and given firing, an absolute deviation between the value of said variable and the value of a statistical variable representative of a mean of different values of said variable.