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PCV
| Fig. 8.4. Driving PCV 1 - suction nozzle; 2 - the air filter; 3 - spool device; 4 - cylinder head cover; 5 - fresh air; 6 - crankcase gases; 7 - fuel mixture
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PCV provides a reduction in exhaust gases of the hydrocarbons by the circulation of fresh air through the crankcase, mixing it with the crankcase gases and the direction of this mixture into the inlet for the secondary combustion in the engine combustion chamber (Fig. 8.4). The system consists mainly of the vacuum hose and the slide device that provides adjustment of gas flow in accordance with the rotational speed of the engine crankshaft and a vacuum degree in the suction pipe.
Technical condition The efficiency of the crankcase ventilation system can be easily checked. This system should be checked regularly, as the valve and vacuum hoses are usually clogged with soot and tar deposits from the gas stream. With a decrease or cessation of flow through the valve, usually decreases the speed of the crankshaft of the engine idling and the engine is idling is unstable. To check the vacuum in the system, remove the air filter cover and locate the small filter crankcase ventilation system, which is located on the inside of the air filter housing. Disconnect the hose to the filter. With the engine idling, close the thumb hole hose - should feel a slight vacuum. If you slowly push your finger, you can hear a hissing sound. This indicates that air is sucked over the entire pipe system. If there is a negative pressure system is OK. Check the cleanliness of the filter element. If there are suspicions that the filter element is dirty, replace it as a low-cost operation, but provides security during engine operation. If at the end of the vacuum hose is weak, then pipe system is clogged, and it requires further verification. Turn off the ignition, get the spool unit of the ventilation system and carefully remove it from the rubber boot. Shake valve and listen to the emerging sound like a knock (clicks). Knocks the ball caused the slide. If there are no knocks at every shaking (do not knock free), replace the valve. Start up the engine and let it run at idle at the removed spool. Close the thumb opening the valve and check the vacuum. It must be significant and felt immediately. If the vacuum on the spool is weak or not there at all, turn off the ignition and disconnect the vacuum hose from the other end of the valve. Start up the engine at idle and check the depression at the end of the hose, which is disconnected from the spool. Lack of vacuum indicates contamination inside the hose or suction motor. If clogged hose, replace it or remove from the engine and blow compressed air. If clogged passageways carburetor or suction pipe, it is necessary to remove these aggregates and rinse thoroughly to remove the tar deposits. If the vacuum hose to the valve without a strong, and at the entrance of the spool when the hose connection is weak, defective valve - needed to be replaced. Buying a new crankcase ventilation valve, make sure that the item corresponds to the type of your engine. Otherwise it may be too low or too high negative pressure, which can lead to engine damage.
Replacement of components Surgery to replace the valve and the valve filter cm. In Sec. 2.
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