System and method for detecting engine cylinder misfire

A method of detecting an engine cylinder misfire in an internal combustion engine comprising the steps of:

• detecting the exhaust gas pressure generated by the internal combustion engine;
• detecting operating characteristics of the internal combustion engine, said operating characteristics including at least one of the rotational speed, fuel consumption rate and coolant temperature of the internal combustion engine;
• calculating a minimum pressure value corresponding to said operating characteristics;
• comparing said minimum pressure value to the exhaust gas pressure;
• and
• generating a signal indicating if said exhaust gas pressure is less than said minimum pressure value to declare the occurrence of an engine cylinder misfire.

A method of detecting an engine cylinder misfire in an internal combustion engine to determine an optimal level of engine operation comprising the steps of:

• decreasing the amount of fuel supplied to one or more cylinders of an internal combustion engine to cause an engine cylinder misfire;
• detecting said engine cylinder misfire in said internal combustion engine caused by an insufficient supply of said fuel by calculating a minimum pressure value corresponding to at least one of the rotational speed, fuel consumption rate and coolant temperature of the internal combustion engine and comparing said minimum pressure value to a measured exhaust gas pressure;
• generating a signal indicating if said exhaust gas pressure is less than said minimum pressure value to declare the occurrence of an engine cylinder misfire;
• and
• increasing said amount of fuel supplied to said one or more cylinders in response to said detected misfire to a level sufficient to enable said internal combustion engine to operate without the occurrence of engine cylinder misfires at an optimal fuel efficiency.

A system for detecting an engine cylinder misfire in an internal combustion engine comprising:

• a pressure sensor mounted in an exhaust manifold of the internal combustion engine;
• engine operation sensors positioned on or within the internal combustion engine for detecting the operating characteristics of the internal combustion engine, said operating characteristics including at least one of the rotational speed, fuel consumption rate and coolant temperature of the internal combustion engine;
• and
• a processor connected with said engine operation sensors and said pressure sensor for calculating a minimum pressure value to determine if an engine misfire has occurred, said processor comprising a comparison means for comparing the exhaust pressure sensed by said pressure sensor to said minimum pressure value to determine if an engine cylinder misfire has occurred.

A method in an internal combustion engine for detecting a full or partial engine cylinder misfire, the internal combustion engine comprised of a pressure sensing means mounted in an exhaust manifold and connected to an engine operation detecting means that is further connected to a data processing means, the method comprising the steps of:

• sensing the peak pressure of exhaust gas generated by the internal combustion engine;
• converting the sensed pressure into a cylinder exhaust value;
• detecting operating characteristics of the internal combustion engine, said operating characteristics including at least one of the rotational speed, fuel consumption rate and coolant temperature of the internal combustion engine;
• calculating an optimum threshold corresponding to said operating characteristics;
• and
• comparing said cylinder exhaust value with said optimum threshold to determine if a partial or complete engine cylinder misfire occurred.