He's probably just deleting his profile on and off. So it's not really blocking. If you want to find out if he's really blocking or doing something, get "better Facebook". It will tell which of your friends is deleting you or whatnot. Or... you could just not give a crap. Since you all don't speak, I'd suggest just blocking him yourself, for good.
It's probably so in his mind you have no way of looking at what he's up to and who he's talking to but will unblock you at random times thinking you won't notice and try and see what your upto and who your talking to as well
I think you should just block him completely or just not check up on him at all. If you keep doing it, it will drive you crazy. I deleted my ex and blocked everyone we both knew. Well, not blocked, but I made it so that their status updates don't show up on my news feed. Then I do everything I can to not check up on them and so far, I haven't. I don't want to keep thinking about anything related to him.
Sounds to me like your guy needs some attention and he is probably waiting for you to add him.. Don't do that because this kind of personality obviously will use it against you or sit in his tower talking about how you added him and stalking him.. Even though he may have strong feelings for you but I guess he is a little baby in a big man's body.
Why do you check up on him if he has blocked you or not.. I say ignore him and don't even check anything and focus on a hobby or your work or something and believe me.. if you re waiting for him to make a move.. He will. He will eventually add you or message you.. or better yet call you..
He is checking up on u, making sure your still there etc... he is properly looking for any change in your life, if you have a new boyfriend or whatever... you should just block him and then its all over! x