Car not starting

My 2003 Toyota Cary won't start. I had this
problem roughing 2 months ago but do to budget
constraints I was unable to get it fixed. I was told
to tap it with a hammer and it would start. Well I
did that, ran around and started it and it worked. I
did that roughly 3 days before it started without
having to tap it.

Now fast forward to now and it won't start again.
But this time tapping it alone and running around
to start it doesn't work. Someone has to be in the
car, Turing the key while I tap it to start.

Why is this? Anything I can do about it? I won't be
able to replace the starter until Jan 15 of
2017(been saving a little from each check that I
could to afford part and labor, I'm in a big financial
bind at the moment)

Any help would be appreciated. Just want to know
why doing it alone doesn't work anymore.