Seat Toledo 1.8 20V runs cold only on 3 cylinders

Hello, I need a tip from you if the engine is cold the engine only runs on 3 cylinders. If it is warm the runs normal and stinks of gasoline. We checked the compression, everything ok. New spark plugs and cables as well as the ignition coil renewed. Can this be on the temperature sensor on the engine? It does not seem to work, the indicator does not go high although the engine is warm. Lg. Achim