Control system and method using exhaust gas temperatures to adjust an air/fuel mixture for an internal combustion engine

Abstract

A control system for an internal combustion engine includes a temperature sensor and an engine controller. The sensor measures the temperature of exhaust gas passing through an exhaust manifold of the engine during each cycle. The controller selectively operates the engine in a first state and a second state. In the first, normal state, a quantity of fuel based on an open loop fuel mass command value is injected into the engine each cycle. In the second state, the controller determines a temperature of the exhaust gas during a normal cycle, injects the quantity and additional fuel into the engine during a second cycle, determines the temperature of the exhaust gas during the second cycle, compares the temperatures, and adjusts the command value for fuel to be injected each cycle when operating the engine in the first state.