Process for determining the operating parameters of an injection device

A process for determining the operating parameters of an injection device of a combustion engine, said injection device including a plurality of fuel injectors, and an electronic control means able to control said injectors by means of injection control signals, said electronic control means being connected to a sensor permitting continuous measurement of a velocity of said combustion engine, said engine operating in accordance with an engine cycle including at least one injection cycle associated with each of said injectors, said injection cycles following each other in a predetermined order, the process comprising the steps of:

• a) selecting an injector to test from said injectors;
• b) calculating a mean velocity associated with a preceding injector arranged before said injector to test in the order of said injection cycles, which is equal to the velocity of said engine averaged over a measurement duration essentially covering one injection cycle associated with said preceding injector;
• c) for said injection cycle associated with said injector to test, applying to said injector to test an injection control signal including at least one test pulse having an adjustable parameter;
• d) calculating a mean velocity associated with said injector to test, which is equal to the velocity of said engine averaged over a measurement duration essentially covering said injection cycle associated with said injector to test;
• e) calculating a difference between the mean velocity calculated in step d) and said mean velocity calculated in step b);
• f) repeating steps b) to d) for at least another engine cycle, each time varying said parameter of the test pulse;
• g) determining a value of said parameter of the test pulse for which said mean velocity difference exceeds a predetermined threshold and storing said parameter value.