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The system EVAP
On vehicles ventilation hoses are connected directly with ambient air, and are connected to a charcoal canister (adsorber). Dispenser activated carbon intended to capture through the hose onto environmentally harmful vapor fuel that are continuously formed by heating the fuel in the tank. When running under certain engine load fuel vapors sucked from the canister with the activated carbon. This process is controlled by a solenoid valve.
Check solenoid valve fuel vapor recovery system (EVAP) Current consumption at 12 V valve is not more than 0.45 A. The solenoid valve of the fuel vapor recovery system (EVAP) is controlled by the electronic control unit. Fuel vapors accumulate in the canister with the activated carbon. When the engine is cold and idling valve is closed, and a pair of fuel do not fall into the expansion chamber. After warming up the engine during normal driving valve opens and the fuel vapor into the engine where there is their combustion.
A WARNING When disconnecting the vacuum hose, label, then set it to the original position. |
| Fig. 2.167. Using a vacuum pump to check the solenoid valve fuel vapor recovery system (EVAP)
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Disconnect the vacuum hose (black with a red stripe) from the solenoid valve and instead connect the vacuum pump with a vacuum hose (Fig. 2.167). Disconnect the harness connector. Connect the vacuum pump to the union, which was connected to a vacuum hose with a red stripe.
| Fig. 2.168. Checking the dilution when voltage is applied to the solenoid valve system EVAP
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Create a vacuum and check the maintenance feeding (Fig. 2.168) and the termination of the supply voltage to the EVAP valve (tab. 2.28). Measure the current consumption of the solenoid valve of the canister with the activated carbon. The rated current at 20 ?� C - not more than 0.45 A. Measure the resistance between the connector pins of the solenoid valve system EVAP. At 20 ?� C it should be 26 ohms.
Table 2.28 Support parameters vacuum depending on energization of the solenoid valve system EVAP
Check the vacuum hose Before testing the engine to warm up until the coolant temperature is equal to 80-95 ?� C. Disconnect the vacuum pump from the hose fitting the intake manifold and instead connect a hand vacuum pump. Start up the engine and make sure that increasing the speed of the crankshaft of the engine vacuum level remains constant.
A WARNING If a vacuum is created, opening the intake manifold may be contaminated and must be cleaned. |
Overflow limiter (push-pull valve) To test the push-pull valve Blow into the inlet and outlet ports. If air flows with little resistance, then the valve is serviceable.
Fuel filler cap To prevent the release of fuel vapors into the atmosphere of the fuel filler cap is equipped with a vacuum relief valve.
| Fig. 2.169. Location gasket (1) the fuel filler cap
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Check the gasket fuel filler cap and filler neck for damage and deformation (Fig. 2.169). If necessary, replace the cover.
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