Honda Accord

1998-1999 of release

Repair and operation of the car

лазерная эпиляция в центре.

System of catching of fuel evaporations (EVAP) - the general information, check of a state and replacement of components

General information

The system accumulates the fuel evaporations accumulating in a power supply system during the parking of the car and provides a conclusion them in the inlet pipeline for burning in the course of normal functioning of the engine.

The special adsorber filled with absorbent carbon which, actually, and collects in itself fuel evaporations surely is a part of any EVAP system. The way of a conclusion of evaporations from an adsorber can vary depending on a design of concrete system. The description given below will allow the reader to understand the principles of functioning of EVAP system of any type rather in details.

The described design not necessarily has to correspond completely to a design of the system installed on the concrete car, however the principle of functioning is the general for all models equipped with system of injection of fuel. In case of identification of any deviations, be verified with information provided on VECI label fixed under a cowl.

The cover of a jellied mouth of a fuel tank is equipped with the bilateral safety valve. In case of refusal systems the valve provides branch of fuel evaporations in the atmosphere.

Other locking valve (ORVR valve) is installed near a fuel tank and provides adjustment of branch of fuel evaporations in a coal adsorber depending on the differences of pressure/depression connected with change of temperature.

On the way to a coal adsorber fuel evaporations are missed via the double-thread valve and on ventilating hoses get to the coal adsorber established in a motive compartment where accumulate during the whole time of the parking.

At start of the engine until its warming up up to the certain temperature the locking electromagnetic valve of a purge of an adsorber remains closed, allowing opening of the diaphragm valve of a purge at the expense of increase in depth of depression in the inlet pipeline. From an adsorber fuel evaporations via the diaphragm valve are blown in the inlet pipeline, from where come to combustion chambers where are burned out in the course of normal functioning of the engine.

The fuel tank is equipped also with the sensor tracing changes of pressure in a tank both during the parking and on the run of the car.

CHECK

PERFORMANCE ORDER

Full check of EVAP system lies outside qualification of the average amateur mechanic. Fortunately, the EVAP system, as well as other systems of decrease in toxicity of the fulfilled gases, is protected by additional guarantee certificates. Most often refusals of EVAP system are connected with damage of an adsorber or failure of vacuum hoses.

1. First of all always check a condition of vacuum hoses, damage or which detachment most often and it appears a cause of failure of system (be verified with the scheme of the laying of hoses given on a label of VECI of your car). In case of need replace the damaged hoses.

2. Disconnect the vacuum line from a coal adsorber and connect the vacuum gage to a hose. At cold (temperature is below 66 °C) and working at single turns the engine, depression has to be absent here, - otherwise it is necessary to check a condition of the electromagnetic valve of management of a purge of an adsorber. If depression is not present, lift engine turns to 3000 in a minute and warm up the unit up to the normal working temperature (the fan of the cooling system has to work). Now the device has to register depression, - otherwise, besides check a condition of the valve of management of a purge (see paragraph 7).

3. Disconnect a vacuum hose from the double-thread EVAP valve (near a coal adsorber) and connect to it the manual vacuum pump. Track that the pump was directly connected to the double-thread valve. At the included ignition (the engine do not start), create depression and make sure that the valve reliably holds it. The valve allowing leaks is subject to replacement.

4. At the included ignition (the engine is not started) disconnect the locking ventilating valve of a coal adsorber (see an accompanying illustration) and make sure that the double-thread valve holds depression. If this condition is satisfied, replace the locking valve together with a sealing ring. Otherwise, check an electrical wiring on a chain site between the locking valve and RSM.

5. Disconnect a vacuum hose from the locking ventilating valve of a coal adsorber, connect the manual vacuum pump and at the included ignition (do not start the engine) make sure that the valve does not allow leaks, otherwise replace it.
6 Disconnect an electrical wiring from the locking ventilating valve of a coal adsorber and at the included ignition (the engine do not start) make sure available battery tension between the plug No. 1 of the socket and weight. If tension is absent, check a condition of an electrical wiring on a chain site between the locking valve and a safety lock No. 6 on 15 A.

7. Disunite the 2-contact socket of the electromagnetic valve of management of a purge of an adsorber and at the included ignition (the engine do not start) make sure of presence of tension of the battery on the socket plug No. 1. In the absence of food check an electrical wiring on a chain site on a site between the electromagnetic valve and a safety lock No. 6 on 15 A.

The electromagnetic valve of management of a purge of a coal adsorber is at the left on a back partition of a motive compartment (on the V6 models), or on the inlet pipeline (on 4-cylinder models).

8. Warm up the engine up to the normal working temperature (the fan of the cooling system has to work). Make sure of return of depression from the electromagnetic valve of management of a purge back in the inlet pipeline. If depression is still absent, disunite the 2-contact electric socket and repeat check of depression in the pipeline. If depression is not present and this time, check a state and correctness of laying of vacuum hoses. If depression takes place, check for existence of short circuit an electrical wiring on a chain site between the 2-contact socket and RSM.

9. Disunite the 2-contact socket on the perepuskny electromagnetic EVAP valve. At the included ignition (the engine do not start) on the plug No. 1 battery tension has to take place. In the absence of food check an electrical wiring on a chain site between the valve and a safety lock No. 6 on 15 A.

10. Disunite the 3-contact socket of an electrical wiring of the sensor of pressure in a fuel tank and at the included ignition (the engine do not start) measure tension between plugs No. No. 1 and 2 of the socket. Afterwards measure tension between plugs No. No. 2 and 3. in both cases the device has to register value about 5 Century. If check yields positive result, however, OBD fixes malfunction of the sensor again, replace the last.
11. Check a coal adsorber for existence of signs of leaks. Remove assembly of an adsorber and a zakuporta traffic jams all its ventilating lines. Connect the manual vacuum pump to the locking ventilating valve of an adsorber, create depression and make sure of lack of leaks. In case of need replace an adsorber.

REPLACEMENT

Coal adsorber

PERFORMANCE ORDER

1. Disconnect all ventilating hoses from assembly of an adsorber, turn out bolts and take assembly from under the car. Track that all disconnected hoses were properly marked.
2. Installation is made upside-down.
The double-thread EVAP valve, the locking ventilating valve, pressure sensor in a fuel tank and perepuskny the electromagnetic EVAP valve
3. For the purpose of ensuring access to the listed valves/sensors remove a coal adsorber, then make dismantle of each of components in an individual order.
4. Installation is made upside-down.
Electromagnetic valve of management of a purge of a coal adsorber
5. Disconnect vacuum hoses from the electromagnetic valve of management of a purge of a coal adsorber.
6. Turn out a fixing bolt and take the valve from a motive compartment.
7. Installation is made upside-down.