printable version

EVAP System (EVAP)

general description

EVAP system carries out adsorption of fuel vapor and burning them in the composition of the fuel mixture during normal engine operation.

The structure of any system EVAP necessarily includes an adsorber filled with activated charcoal, which collects gasoline vapors. The difference between one system from another may be to implement output management fumes. The following are descriptions of typical model is described in the manual car brands, which must provide the owner with sufficient information to understand the principle of withdrawal of fuel vapor on his car.

The following description does not purport to-one matching the description of the system used on the particular vehicle, but gives an idea of the typical scheme adopted for the output of the fuel vapor in the models equipped with the fuel injection system. Despite the fact that the presence of all these components is mandatory in any system EVAP, on a particular vehicle may well include additional devices that are unique. Check the data label and the circuit pads VECI vacuum hoses located under the hood of the car.

Gulf fuel filler cap is equipped with two-way safety valve. The valve is used to output the atmosphere accumulated in the fuel tank fumes in the event of system EVAP.

Another clipping (discharge) valve is positioned in the fuel tank and used to control the output of the fuel vapor from the tank to a carbon adsorber, depending on the presence in the tank of excess or negative pressure (depending on ambient temperature).

After passing through the two-way valve on the fuel evaporation ventilation hose comes in a coal adsorber is located in the engine compartment, where they are adsorbed with activated carbon and kept to output to the engine combustion chamber.

Location coal adsorber system EVAP.

When the engine is started and warmed up to a predetermined temperature shut-off solenoid valve near the canister purge is closed, allowing the opening of the intake pipe vacuum diaphragm control valve canister purge. This fuel vapor derived from the adsorber is also under the influence of vacuum inlet pipeline.

Canister purge control solenoid is located on the left side of the engine adjacent to the TPS.

Check

Full test EVAP system lies outside the qualification of the average mechanic-fan. Fortunately vapor recovery system, like any other subsystem of reducing emissions falls under the warranty of the manufacturer (5 years or 80,000 km (50,000 miles) at the time of this manual). Perhaps the system does not fail even once during the entire life of the vehicle, however, in any case, from time to time to check the condition of hoses and its coal adsorber.

Always first check the condition of hoses, disconnect or damage which is most often the cause of failure of the EVAP. To verify connection of hoses consult with the circuit pads vacuum hoses deposited on the nameplate fixed to the radiator support under the hood of the car. If necessary, make a repair or replacement of damaged tubes.

PERFORMANCE ORDER

Disconnect the vacuum hose from the canister purge valve diaphragm (located on the inlet pipe) and connect the hose to a vacuum gauge. Start the engine and leave it running at idle. Negative pressure in the hose should not be! The temperature of the engine at this check must reach 75,5 ?� C When the engine is warm should be no vacuum (negative pressure signal from the control solenoid canister bleed). If depression is absent, proceed to the procedure n. If depression occurs, disunite an electric socket purge control solenoid and check for power from the battery. Check the battery voltage to control the canister purge solenoid. If the voltage is the case, replace the shut-off solenoid valve. If no voltage, check the PCM harness, if necessary, make repairs. Warm up the engine to normal operating temperature. If the original vacuum at the purge control valve diaphragm missing, check the vacuum source. If depression occurs, go to n. If there is no vacuum, check the vacuum line going to the intake manifold for damage or violation of cross fittings. If the vacuum is a vacuum in the initial state takes place, check the operation of the rotary valve of a fuel tank in the workshop of dealer branch.

The discharge valve of a fuel tank

PERFORMANCE ORDER

Remove the fuel tank (Head of the Power supply system and exhaust). The valve is put in the rubber grommet. Remove it, hooked on one side and removing the sleeve from the tank with a valve. The discharge valve of a fuel tank located in the fuel tank. Install in reverse order.