Patent ID: 9279406
Filing Date: 2016-03-08
CPC Classification: F02P,G01M,G07C

Claim Text:
1. A method of identifying cyclic variations in combustion efficiency in cylinders of an internal combustion engine with aid of instrumentation, the engine including an air induction system, the cylinders, means for generating ignition events for the cylinders, and an exhaust system, the instrumentation including one or more microprocessors programmed with one or more software routines, memory, and means for measuring cylinder pressure pulses; the method including: running the engine through a number of combustion cycles; measuring the pressure pulses with the means for measuring cylinder pressure pulses; generating a waveform from the cylinder pressure pulses that are measured; dividing the waveform of the cylinder pressure pulses that are measured into waveform cycles and cycle segments, wherein each of the waveform cycles represents a complete combustion cycle of the engine, wherein each of the cycle segments represents a combustion cycle of a separate cylinder of the cylinders in the engine, and wherein a total number of the cycle segments during the complete combustion cycle of the engine equals a total number of the cylinders; performing an identifier sequence by marking the cycle segments from the complete combustion cycle of the engine with separate and distinct identifiers associated with different cycles of the cylinders, and repeating the identifier sequence for a number of successive complete combustion cycles of the engine; and comparing each individual cycle segment of the cycle segments during a particular complete combustion cycle of the engine with the cycle segment having a same identifier for the number of the successive complete combustion cycles of the engine to identify cycle-to-cycle variations of the pressure pulses in the cycle segments for each of the cylinders: determining a carbon buildup in the air induction system of the engine from the cycle-to-cycle pressure variations; chemically cleaning the air induction system based on carbon buildup from the air induction system; repeating measuring the pressure pulses, generating the waveform, dividing the waveform into the waveform cycles and the cycle segments, performing the identifier sequence by marking the cycle segments, comparing each individual cycle segment, and determining the carbon buildup in the air induction system from the cycle to cycle variations after cleaning the air induction system.