My 2001 Hyundai Tiburon won't start for me. Every time I take it to the Hyundai dealership it's starts perfectly and they have exhausted all of their options that could be causing it to not start....

...So I take it home and then a few
days later same thing happens, it
cranks and cranks but won't fire. So I
let it sit for a day or two, but nothing.
I get it towed to Hyundai dealer,
won't start. Next day it starts just fine
for them and they can't duplicate the
problem. They have called in
specialists and called consultants.
Nobody can explain or fix this
mystery problem. I have an unreliable
car that leaves me stranded. 50%
chance my car will start every time I
get in it. So frustrating! What is its
problem?!! Has 118k miles on it and
is in great condition other then that.
Help!