Toyota Land Cruiser 100 / Amazon, Lexus LX 470

Since 1997 of release

Repair and car operation

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

The general information

The typical scheme of an arrangement of components of system EVAP

System EVAP accumulates accumulating in the power supply system during car parking fuel evaporations and provides their conclusion in an inlet path for burning in the course of normal functioning of the engine (address illustrations above). System improvement is made continuously in process of toughening of the requirements shown to protection of environment.

On models of early years of release system EVAP consisted of the coal adsorber equipped with the control valve and the lines of communication connecting it with a fuel tank of the car. Also into system structure entered the gauge of temperature of a cooling liquid (EATS), the vacuum valve-switch (VSV) and the management module (ЕСМ). On models of last years of release the gauge of pressure of the fuel evaporations is in addition included in system structure, established on a back partition of an impellent compartment. The scheme of an arrangement of components is presented on an illustration. The pressure gauge traces changes of pressure in the system, connected with development of leaks. The number of components subject to monitoring includes the fuel tank, all vacuum lines brought to an adsorber and the throttle case. EVAP is a part of system of onboard diagnostics OBD-II (see Sections System of onboard diagnostics (OBD) - a principle of functioning and codes of malfunctions and Information gauges - the general information and check of serviceability of functioning) and for check of serviceability of its functioning on models of last years of release, accordingly, is required the special scanner.

During car parking fuel evaporations are taken away from cavities of a petrol tank and the throttle case in a coal adsorber where accumulate till the moment of start of the engine. When the engine starts to rotate, the adsorber is blown also its contents deduced in the inlet pipeline, whence arrives in combustion chambers.

The coal adsorber is equipped by the control valve into which design two balls enter. Depending on current service conditions of the engine and pressure in a fuel tank the valve opens and closed, regulating process of tap of steams of fuel of a tank and the throttle case.

Check

Infringement of stability of turns of idling, decrease in efficiency of return of the engine, spontaneous остановы the last can be caused by refusal of the control valve, damage of a coal adsorber or connecting hoses of system EVAP, and also a wrong lining of the last. Check up also a condition of a cover of a jellied mouth of a fuel tank.

Obvious losses of fuel, no less than occurrence of its strong smell during parking can be caused by leaks топливопроводов, or damage of the case of a coal adsorber, malfunction of the control valve, a detachment, or passableness infringement испарительных lines, and also a wrong lining of the last.

Replacement of a coal adsorber