2004 Nissan Sentra sometimes wont start first time when cold

Hi all. I am hoping to get some opinions from people who know more than I. I have a 2004 Nissan Sentra 1.8 with about 68000 miles that, sometimes, when it has not been started for a while will not start on the first try. It turns over and cranks away and sometimes starts if I hold it but most times I have to turn the key back and try again. It has always started the second time without an issue and it doesnt do this everytime. Also, if it exhibits the problem and I drive it and turn it off for a short while it starts right up the next time. It has been doing this for well over a year now. The reason I am asking is we are about to have our first baby and my wife is literally freaking out about this issue. I took the car to a mechanic about 10 mo. ago and he said he could not duplicate the problem and that he didnt see anything wrong with it.

I cleaned the fuel system thinking that might help but to no avail. I was thinking it could be a dirty fuel filter? or fuel pump going? I asked another mechanic and they said they could run a psi test on the fuel lines to see if it is getting sufficient pressure, but I am afraid the problem wont duplicate when they run test or that it wont give good results and that I would be wasting more money.

If anyone has experienced this, or something similar I would really appreciate any advice or sources of useful help and information.

Thanks in advance

Have you had the ECU checked for pending codes? Often times when there is a no start problem a soft or pending code is stored. The soft code does get deleted after a number of start and drive cycles so you may not have one now if it hasn't occurred recently. Many of the chain autoparts stores will pull the codes for you, so I suggest you get that done first and report back.