Abstract: A system for detecting conditions indicative of substandard performance of cylinders in an internal combustion engine includes an engine control unit disposed in operable communication with the engine and a computer disposed in informational communication with the engine control unit. A method for utilizing the system includes comparing fuel requirements of the engine operating under power of all cylinders and under the successive arrest of each of the cylinders or sets of cylinders. The process is repeated until each cylinder or set of cylinders is arrested and all of the data can be compiled and considered to determine the performance of each cylinder or set of cylinders. The system measures the required fuel with all cylinders operating and enables a recommendation to be made with respect to corrective or maintenance measures that should be undertaken with respect to the isolation of the individual cylinder(s) which may be determined to be weak or non-functioning.