Short-term fuel trim of petrol engine by oxygen sensor voltage during vehicle operation

The object of the study was fuel trim of the air-fuel mixture, in particular, short-term fuel trim by voltage change of the oxygen sensor installed before the catalytic converter during vehicle operation. Experimental studies were on the Bishkek – Osh (Kyrgyz Republic) highway at an altitude of 750–3200 m above sea level. It is characterized by flat, mountainous and high mountainous vehicle operating conditions. The experimental studies results were used to graph the dependence of short-term fuel trim on the change of oxygen sensor voltage during vehicle operation. The values of fuel trim parameters can be used to assess the state of the air-fuel mixture, as well as to make a conclusion about the technical condition of sensors, systems and mechanisms of the engine and elements of the car exhaust system. In addition, in normal operation of the engine, when the fluctuation of fuel correction indicators is ±10 %, fuel-economic and environmental indicators will be in fit. It should also be recognized that the modern automobile engines have a system of various sensors and electronic engine control unit, but they have their certain disadvantages in ensuring the stoichiometric composition of the air-fuel mixture (λ = 1).

electronic engine control unit, stoichiometric fuel-air mixture composition, air-fuel ratio, optimum fuel-air mixture composition, pulse duration of injector opening, fuel trim, short-term fuel trim, oxygen sensor voltage