Exhaust gas recirculation

The system serves as the exhaust gas recirculation to reduce emissions of toxic substances in exhaust gases by supplying a small part of the exhaust gases from the exhaust manifold to the engine cylinders. During the combustion of the working mixture in the cylinders at a temperature of 2500 ° C produced nitric oxide - a poisonous gas (NO2). Its concentration increases if air / fuel ratio is different from the stoichiometric (14,7:1). When a small amount of exhaust gas is mixed to the working mixture, the combustion conditions are deteriorating due to repeated exhaust gases of combustion, the combustion temperature is lowered and accordingly the output of the oxides of nitrogen. Scheme of work processed gas recirculation valve 1. Recirculation Valve 2. Membrane 3. Stem 4. Throttling element 5. Recirculation inlet pipeline must operate only at a temperature of cooling. fluid is not less than 40 ° C, average loads the engine. The recirculation system is not working at idle and at full throttle opening. In vehicles 80 - and 90 - s used pneumatic control systems recyclers. In later models the valve is controlled recycling of the electronic control unit. Connect the valve to the nozzles, in which depression appears immediately after a small throttle openings causes failures when accelerating. A large number of soot inside the valve can cause leakage of the intake manifold, even when properly connected vacuum tubes. The most difficult control scheme made the valve on Japanese cars. Valve opening time was determined not only by the position the throttle and engine temperature, and pressure of the exhaust gases. Since the functioning of the recycling system is not a prerequisite for normal engine operation, in some cases it is recommended during the diagnostic and troubleshooting turn off the valve and recirculation muffle its working channel an additional gasket paronita. This is done to eliminate the influence of a possible malfunction of the recirculation system to work the carburetor.