Fallout 3 on 360 just isn't downloading whatsoever.

Something to do with Fast Start? Can you open the game while you are downloading it?

make sure you have enough hard disk space

I deleted all fallout related things off my console and I restarted my console multiple times. Nothing. I think it's just fallout 3 at this point.

It never says "download stopped" at 80% it just goes to 0% then does nothing.

Hi Cyuu, so first the above mentioned step of powering off and then on your xbox is a good idea. It won't lose your data (unless there is a hardware or more serious operating system issue), it is just a more complete full restart.

Then, try to sign out of your Profile, restart, and sign back in and test again. You might have to completely remove all the game and DLC for that game as part of that test.

You have checked you have enough free hard drive space? Often during game install, it takes a lot more space than it says, to do the download, then the unpack and install, then the clean up.

Also, you could try if possible, connecting your xbox via ethernet network cable to your internet modem? Just in case it were an issue with the large download over wireless / wifi.

The full clean factory reset of your xbox would be one of the last steps, as that obviously means you'd have to re-download everything, but it would also give the best 'clean start' chance at successfully getting it to work.

Those ideas are for any game/issue in general. Of course it is also a good idea to contact the Developer of the software/game for assistance.

Those are for xbox one, they wouldn't work for 360.