Measures to improve the composition of exhaust gases

To reduce the content of nitrogen oxides (NOx) in the exhaust gases, the diesel engine fuel system is equipped with an exhaust gas recirculation system (EGR system). The EGR valve is located on the intake manifold. The function of the valve is to divert some of the exhaust gases back into the combustion chambers of the engine in order to reduce the combustion temperature and, as a result, reduce the content of toxic substances in the exhaust gases.

To reduce the content of other poisonous substances in the exhaust gases, such as particles and hydrocarbons (NS), requires precise electronic control and the use of an oxidation catalyst. The electronic control device receives information from various sensors and regulates fuel injection according to the specified technical characteristics.

A measuring device is located in the suction pipe, which measures the mass of the sucked-in air according to the following principle: an electrically heated coil is cooled by a passing air stream. In order to keep the coil temperature constant, the heating current changes according to the density/temperature of the sucked air. Based on the fluctuations in the heating current, the control device determines the mass of the sucked-in air.

The sensor measures the position of the high pressure fuel pump lever actuated by the accelerator pedal.

An inductive sensor is located on the engine flywheel. It provides information about the current engine speed.

The diesel injection control unit selects the optimum fuel injection timing for any vehicle operating condition by adjusting the cold engine run magnetic switch and the partial load solenoid valve in the high pressure fuel pump.

The exhaust gas recirculation system is controlled by a control device through two valves, the so-called. vacuum converter and exhaust gas recirculation valve.