Search Results

The recent availability of fast response (< 1.0 seconds) exhaust gas temperature sensors for exhaust gas temperature measurement enables a new method for closed loop feedback engine control in small engines and other non-stoichiometric applications (V-8 marine fuel injected engines for example). Conventional closed loop stoichiometric A/F control with traditional switching type oxygen sensors is often not applicable because these engines rarely if ever operate at stoichiometric A/F ratios. Richer A/F ratio control is necessary for maximum power and combustion temperature cooling. Wide range UEGO A/F sensors are an alternate solution but the cost of these sensors may be too high. Additionally, the very short exhaust systems found on many small engines can allow ambient air to back flow into the exhaust due to pressure pulsations and corrupt the signal from an oxygen concentration type sensor.