You need to load a timer reload value. Even though the port pin is swinging up and down (and I assume it is properly connected to light the LED), the LED will appear to be lit steady if the pin is toggling at too high of speed.

For a typical human being, if the LED is switching on and off faster than about 25 Hz the eye will see it as being on steady. The LED may not be as bright as if there were no high speed switching but it will appear ON over some switching rate.

Michael Karas