Fuel Tank: Operation

This model passes a full 360 degree roll over test without fuel leakage. To accomplish this, fuel and vapor flow controls are required for all fuel tank connections.

An evaporation control system is connected to the roll over valve(s)/control valve to reduce emissions of fuel vapors into the atmosphere, when the tank is vented due to vapor expansion in the tank. When fuel evaporates from the fuel tank, vapors pass through vent hoses or tubes to a charcoal canister where they are temporarily held. When the engine is running, the vapors are drawn into the intake manifold. In addition, fuel vapors produced during vehicle refueling are allowed to pass through the vent hoses/tubes to the charcoal canister(s) for temporary storage (prior to being drawn into the intake manifold). This is equipped with a self-diagnosing system using a Natural Vacuum Leak Detection (NVLD). See EMISSIONS CONTROL article for additional information.