engine problems

when you first start the car up, its fine. But
after it has been running for a few and for
the rest of the day when you're out running
around every time you shut the car off, if
you wait 5 minutes and start it back up you
will have to start it twice to get it going. So
when you first turn the ignitiob on it starts
up but then it dies. then when u try again
it's fine.and if you let it sit and idle for a
while sometimes it will turn itself off, also
when you pull into a parking space at low
idle it will turn itself off sometimes. And
also sometimes when it does turn itself off
at idle,it will sputter and  a vapor mist will
come out underneath the hood on the
passenger side and dissipate quickly.I have
put a new MAF sensor, a new MAP sensor,
a crankshaft sensor, a fuel pump and a fuel
filter on and still has the same problem.any
ideas?