Method for analyzing injector performance

摘要

Injector drift for a diesel engine are detected by reconfiguration of injection patterns from one pattern into a pattern with a different number of pulse points while attempting to hold total fuel injected constant. If a particular injector is subject to drift then changes in the pulse pattern result in an increase or decrease in fuel injected and consequential variations in engine speed. By applying alternating injection patterns at constant fuel demand and allowing engine speed time to stabilize, a rhythmic variation in engine speed/torque will appear which can be detected using one of a number of techniques.

主权项

1. A method for detecting injector drift on an internal combustion engine, the methodcomprising the steps of:
establishing at least first and second patterns of fuel injection pulses for application to a cylinder of the internal combustion engine with the first and second patterns differing in number of fuel injection pulses while having the same nominal target amount of fuel to deliver; operating the engine at a target level steady state condition with the injectors for all cylinders being active; selecting a first cylinder to test; injecting fuel to the selected cylinder using each of the first and second patterns at least once during a period; determining if engine speed varies with correlation to the first and second patterns of fuel injection pulses injected into the first cylinder; terminating variation of fuel injection into the first cylinder with both first and second patterns of fuel injection pulses; selecting a second cylinder to test; injecting fuel into the second cylinder using each of the first and second patterns at least once during a period; determining if engine speed varies with correlation to the first and second patterns of fuel injection pulses injected into the second cylinder.