Do you see the check engine light indicator turn on when you turn the key to the accessory position?
good one!
In response to your e-mail--
the motor you hear running intermittently is the fuel pump--
now--what we need to do before dropping the tank and replacing it is to verify it isn't a voltage supply problem
when you first switch the key to "on" you should observe 2 things
1) the check engine light should remain lit
2) the fuel pump should prime itself, for 1-2 seconds
If the first isn't happening every time-check the PCM relay and it's connections
if it is just the fuel pump which is intermittent, check the fuel pump relay, and it's socket connections.
As a "jiggle" test, you could leave the key in the on position and jiggle the relays, observing for a clicking when you do this--
You probably do have a fuel pump going south-but it is a good idea to be sure-because they aren't exactly free of charge--
So, after the above checks--you need to check the supply voltage at the fuel pump. With a meter connected, switch the key to on. The voltage should go to 12 v for 1-2 seconds, and then drop to around 6v. It may be a good idea to have a helper for this-so you can keep your eye on the meter--