Cycle the key a couple times before cranking the engine over for the first time. If this allows it to catch immediately, a bad check-valve in the fuel pump assembly or just a weak pump are possible.
Changing the fuel filter can also help a weak pump.
i had a similar problem. i would drive the car for a good bit, park it and try to start it after a few minutes and it wouldnt start on the first time. on the second time it would start right up.
i would as HISSIN50 said, cylce the key twice and on the second time it would start.
i switched out the stock fuel pump for a gss340 walbro pump (255lph hi-pressure) and changed the fuel filter at the same time. never had the problem again.
are you going to the car show this sunday behind garden city? i'll be there. just got to clean up the car and add a few more bling pieces.