An EVAP system prevents fuel vapors from escaping into the atmosphere
Fuel vapors are absorbed by the carbon adsorber
The adsorber is installed in the engine compartment and is connected by pipelines to the fuel tank and the purge solenoid valve
The canister purge solenoid valve installed on the air supply hose switches the system operation modes based on signals from the engine control unit.
Fuel vapors from the fuel tank are constantly discharged through the pipeline and accumulate in the adsorber filled with activated carbon (adsorbent)
When the engine is running, the adsorbent is periodically regenerated (recovered) by blowing the adsorber with fresh air from the atmosphere
Air enters the system under the action of vacuum transmitted through the pipeline from the intake manifold to the adsorber cavity when the purge valve installed in the pipeline is opened
The electronic engine control unit regulates the intensity of the adsorber purge depending on the engine operating mode, supplying a signal to the valve with a variable pulse frequency.
Fuel vapors from the canister through the pipeline enter the engine intake manifold and burn in the cylinders.
Failures in the evaporative emission system lead to unstable idling up to engine shutdown, increased toxicity of exhaust gases and deterioration in driving performance of the car.
Replacing the canister of the fuel vapor recovery system
The evaporative emission system canister is removed for inspection or replacement when a persistent smell of gasoline occurs due to canister leaks.
In addition, a violation of the tightness of the adsorber can cause unstable operation of the engine at idle until it stops.
Loosen the fastening clamp and slide the clamp along the hose
Disconnect the fuel tank vent pipe from the adsorber
We also disconnect the other two pipelines from the adsorber
We unscrew the two nuts securing the adsorber to the body and remove the adsorber
Install the adsorber in reverse order
Removing the canister purge valve
Disconnect the negative battery terminal
We loosen the fastening clamp and remove the pipeline connecting the valve with the adsorber from the valve fitting
We also remove the pipeline connecting the valve to the intake manifold
Press the lock of the wire block and disconnect it from the contacts of the canister purge valve connector
Pull up the canister purge valve and remove it from the air supply hose
When replacing the adsorber, pay attention to its marking
Install the canister purge valve in reverse order