This system is designed to trap and store fuel that evaporates from the fuel tank, throttle body, and intake manifold, preventing hydrocarbon emissions from entering the atmosphere. The Evaporative Emission Control (EVAP) system includes a charcoal-filled canister, connecting lines, a Temperature Vacuum Valve, a Vacuum Control Valve, a Vacuum Switching Valve, and a check valve. Fuel vapors are stored in the canister when the engine is off and purged for combustion when the engine is running. The charcoal canister features a check valve with three check balls that regulate passageways based on fuel tank pressure and running conditions. Issues such as poor idle, stalling, and driveability can arise from an inoperative check valve, damaged canister, or faulty hoses. Signs of fuel loss or odor may indicate leaks from fuel lines or the canister, necessitating inspection of hoses for kinks or cracks. Any fuel leakage from the canister requires replacement, and a clogged filter or stuck check valve should be addressed by testing airflow through the canister. The operation of the Temperature Vacuum Valve should be verified by checking airflow at different engine temperatures, replacing the valve if necessary. For canister replacement, vacuum hoses should be labeled and detached, followed by removal of mounting bolts and disconnection of hoses before installing the new canister in reverse order.
Posted by ToyotaPartsDeal Specialist