Fuel tank isolation valve controls and diagnostics

Methods and systems are provided for an evaporative emissions system of a vehicle. In an exemplary embodiment, the evaporative emissions system includes an engine; a fuel tank configured to provide fuel for the engine; a plurality of sensors configured to generate sensor data for the evaporative emissions system; a carbon canister configured to capture carbon emissions from the fuel tank; a first valve disposed between the carbon canister and the engine; a second valve disposed between the fuel tank and the carbon canister; and one or more processors that are configured to at least facilitate selectively controlling opening and closing of the first and second valves, to thereby control carbon emissions from the carbon canister and maintain performance of the engine, using the sensor data.