System and process for detection of weak cylinders in a diesel engine

A method of analyzing the operation of a multi-cylinder engine to identify cylinders delivering substandard performance, the method comprising:

• operating the engine in an analysis mode at substantially constant speed or load;
• gathering data indicative of fuel usage of the engine cylinders when the engine is operating on all cylinders in said analysis mode;
• gathering data indicative of the fuel usage of the engine cylinders when the engine is operating with the operation of at least one cylinder arrested in said analysis mode until data gathering has been performed with each of the cylinders successively arrested wherein the data gathered is representative of the average fuel usage of all operating cylinders for a series of cylinder firings of a selected number;
• and
• analyzing said gathered data to identify the engine operations for which fuel usage was affected to a lesser degree by the arrest of cylinder operation to identify cylinders delivering substandard performance.

A method of analyzing the operation of a multi-cylinder engine to identify cylinders delivering substandard performance, the method comprising:

• operating the engine in an analysis mode at substantially constant speed or load wherein the engine comprises a fuel injection system for each cylinder and wherein the duration of time during which each system delivers fuel is measured, with the duration of time being representative of the quantity of fuel delivered to the respective cylinder;
• gathering data indicative of fuel usage of the engine cylinders when the engine is operating on all cylinders in said analysis mode;
• gathering data indicative of the fuel usage of the engine cylinders when the engine is operating with the operation of at least one cylinder arrested in said analysis mode until data gathering has been performed with each of the cylinders successively arrested;
• and
• analyzing said gathered data to identify the engine operations for which fuel usage was affected to a lesser degree by the arrest of cylinder operation to identify cylinders delivering substandard performance.

A method for analyzing the performance of individual cylinders of an engine, comprising:

• maintaining the engine at at least one of a selected load and a selected speed;
• arresting and restoring one of the cylinders of the engine for a period of time until each of the cylinders of the engine have been arrested and restored while the others of the cylinders operate;
• calculating an average fuel volume required by the operating cylinders during said period of time when the one cylinder is arrested;
• and
• comparing said average fuel volume with an average fuel volume of each of the other cylinders.