Intermittent starting problem

Two times in the past 4-5 months my 08 prerunner has left me sitting. First time, it sat all day and when I tride to leave work it wouldn't start. It would crank and crank but wouldn't start. One of the mechanics at work said it sounded like a fuel pump. He kicked around the gas tank a little and it started right up (coincidence??). Well it happened again yesterday with a full tank, it would crank and crank but not start. I couldnt hear if the fuel pump was starting up. I think you should hear it click when you turn the key on. I left the truck at work overnight and this morning it started right up and has started fine many times.
What are some suggestions??
2008 Tacoma Prerunner
6 Cyl.
100K

 

Not sure if it's the same... but it seems like a while back I was having some issues with my 10 as it would stumble when it started... I had to crank it a few times on the rare occasion... I've since replaced the plugs and haven't encountered the issue. My truck had less than 30k at the time. It's a cheap "fix" to look at.

 

Yes the plugs have been replaced