Amigo 4WD L4-2559cc 2.6L SOHC (4ZE1) (1993)
Evaporative Check Valve: Description and Operation
Check And Relief Valve
PURPOSE
Prevents fuel from entering the vapor line leading from the tank to the canister. Also allows air to enter the fuel tank as it it is consumed.
LOCATION
In the vapor line, between the tank and canister.
OPERATION
-
When the engine is not running:
Fuel vapor from the rollover fuel trap is fed to the check and relief valve. When vapor pressure reaches 40 mmHg (1.6 in.Hg), the check
valve opens to allow vapors into the canister.
-
When the engine is running:
When the pressure differential between the relief side and the fuel tank becomes 20 mmHg (0.8 in.Hg), the relief valve opens to allow air
from the air cleaner into the fuel tank. This restores atmospheric pressure to the fuel tank.