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U.S. Department of Energy
Office of Scientific and Technical Information

Internal combustion engine misfire detector

Patent ·
OSTI ID:6139752

The method is described of detecting a misfire condition in a spark ignited internal combustion engine where the idle speed of the engine is controlled by an idle speed control means that varies the spark timing advance developed by a spark timing control means for the ignition system of the engine to control engine idle speed, the steps comprising, operating the engine in an idle speed mode, while operating the engine in the idle speed mode causing the spark timing control means to vary the spark timing advance as a function of sensed engine speed to control idle engine speed, repeatedly sampling spark timing advance values developed by the spark timing control means for a predetermined number of data samples, determining the absolute difference in spark timing advance values between each pair of consecutively occurring data samples during the occurrence of the predetermined number of data samples, and adding together difference values that are related to each the absolute difference in spark timing advance values to provide a sum total of consecutively occurring difference values, the magnitude of the sum total being indicative of whether or not the engine is misfiring.

Assignee:
General Motors Corp., Detroit, MI (United States)
Patent Number(s):
A; US 5226322
Application Number:
PPN: US 7-809713
OSTI ID:
6139752
Country of Publication:
United States
Language:
English