5.3.8. System of recirculation of the fulfilled gases
Fig. 4.132. System of recirculation of the fulfilled gases: 1 — the recirculation valve; 2 — the carburetor; 3 — a hose from the thermal vacuum switch to the carburetor; 4 — an inlet pipe; 5 — a shirt of heating of an inlet pipe; 6 — a hose from the thermal vacuum switch to the recirculation valve; 7 — the thermal vacuum switch; 8 — a tube of a supply of the recirculated gases from a final collector
The System of Recirculation of the Fulfilled Gases (SRFG) (fig. 4.132) serves for decrease in emission of toxic substances with the fulfilled gases by giving of a part of the fulfilled gases from a final collector in engine cylinders.
Recirculation of the fulfilled gases is carried out on the engine which is warmed up up to the temperature of cooling liquid not below 35 — 40 °C on partial loadings.
The system of recirculation of the fulfilled gases does not idle also at full opening of butterfly valves.
Control of work of system of recirculation of the fulfilled gases is exercised of the operating depression from the first camera of the carburetor 2 transmitted via the thermal vacuum switch 7 installed in a shirt 5 of heating of an inlet pipe on hoses 3 and 6 to the valve of 1 recirculation installed on an inlet pipe 4. At the same time a part of the fulfilled gases brought on a tube 8 from a final collector via the open valve of recirculation comes to an inlet path and further to engine cylinders.
In the absence of the operating depression in a hose the 6th valve of recirculation under the influence of a tsindrichesky spring is closed and the system of recirculation of the fulfilled gases does not work. For check of operability of system of recirculation of the fulfilled gases on the engine which is warmed up up to the temperature of cooling liquid of 50 — 60 °C it is necessary to increase sharply the frequency of rotation of a bent shaft — from the small frequency of rotation idling to 2500 min.-1 and to watch visually movement of a rod of the valve of 1 recirculation.
In case of lack of movement of a rod it is necessary to check presence of the managing director of depression on the same modes on the diaphragm mechanism of the valve of recirculation. If depression is available, then the valve is faulty, and it needs to be replaced; if there is no depression, then the thermal vacuum switch is faulty, and it needs to be replaced.
Operation of the car with faulty system of recirculation of the fulfilled gases leads to unstable operation of the engine idling, to an excessive consumption of fuel and the increased emission of toxic substances.