Fuel Tank
The fuel tank is equipped with fuel and vapor controls that allow vehicle to pass a full 360° rollover without fuel leakage. The fuel filler cap also acts as a pressure/vacuum valve. When air pressure inside fuel tank gets too high or too low, fuel cap valve opens to relieve difference in pressure.
An evaporation control system restricts fuel evaporation into atmosphere and reduces unburned hydrocarbons. Vapors from fuel tank are collected in a charcoal filled canister. The vapors are held in canister until engine is operating. When engine is running, vapors are drawn through intake manifold into combustion chambers.
The ORVR control valve manages flow of vapor during refueling. It also controls maximum fuel volume of fuel tank. See Fig 1 .