Is there something wrong with my fireplace?

I have a Temco wood burning fireplace that will billow smoke into the house if the gl doors are left open and only the mesh screen closed with a fire going. It drafts fine with the gl doors closed but then all of the heat goes up the chimney. Also it will draft somewhat better if I open all of the doors and windows in the house, but this defeats the purpose of burning the wood and it still allows some smoking into the house. I've had many fireplaces before and never have had this problem. The flue is wide open when I have a fire going in the fire box. I have looked up the chimney pipe and see no visible obstructions all the way to the top. I'm stumped and it's getting cold in the house...LOL!!! Anybody have any ideas??