I need some help. I want to know if a chunk of land is for sale and there is no sign that says no hunting ,no purple paint, no homes or barns on it and the fence is old and down can i hunt on it?

Someone owns it, and without permission no you can not legally hunt it.

where I lived before any land that is not posted or painted it open to the public even if someone owned it guess that is different in Texas

No I wouldn't. Check out Penal Code 30.05 you will find your answer.

Don't try it in louisiana either. Louisiana is even more strict than Texas about trespassing.

You can contact the county appraisal, and they can give you the contact info of the owners of the land, and can also tell you if the taxes are up to date.

The county has plot books that will tell you the owners name. As far as hunting someones property that ain't posted or fenced I wouldn't without permission but know people that do. I know a guy that would dove hunt north or dallas on EDS property where they have the long horn cattle. Told me he could limit out in 30 minutes, even invited me. I told him no thanks. He hunted there until he got his second warning by the police.

Granite,
I think I understand where your thinking is on this. Texas Penal Code on Trespassing does put some burden on the landowner to "impart notice" that trespassing is forbidden.
But Texas Parks and Wildlife Code covers the landowner on that when dealing with poachers. Note that the intent of hunting without permission constitutes poaching, not just taking an animal.

61.022. TAKING WILDLIFE RESOURCES WITHOUT CONSENT OF
LANDOWNER PROHIBITED. (a) No person may hunt or catch by any means
or method or possess a wildlife resource at any time and at any
place covered by this chapter unless the owner of the land,
submerged land, or water, or the owner's agent, consents.
http://law.onecle.com/texas/parks/61.022.00.html

You can't do it without permission.

Great thanks for all your help.