remove the rear seat, you will hear the fuel pump a lot better, just lift it up and it will pop up... slide it out a little, and then you can lift one side at a time. the fuel pump is very loud so with the car off, windows up, and rear seat raised, you will easily hear it.
secondly... it could be an issue with your starter as well. mine is acting up a little when the car is warm. it will start to turn over, but then just die out. takes a couple times to have it start when the car is warm.