A fuel injector and turbine engine incorporating the fuel injector are provided. The fuel injector includes an active cooling system that insulates fuel flowing through the fuel injector from heat energy within the turbine engine. The cooling system includes a cooling air passage that includes an inlet and an outlet. The inlet and outlet are in fluid communication with the interior of an engine case of the turbine engine. The inlet is at a higher air pressure location than the outlet such that air is siphoned through the cooling air passage. A portion of the cooling air passage includes a heat exchanger for extracting heat energy from the cooling air. The cooling air passes through the fuel injector after it has passed through the heat exchanger. The heat exchanger is positioned external to the engine case and in thermal communication with the ambient.