fuel pump....or is it?

ok, so here's the situation. I live in LA where there is nasty bumper to bumper traffic. When my car gets hot after sitting there (as I am known to do) it starts making a weird noise that I can only equate to something that sounds like an owl hooting. I've been told it's my fuel pump, but I've also been told that it could just be a vaccuum leak. What do you guys think?

......... When my car gets hot after sitting...... it starts making a weird noise that I can only equate to something that sounds like an owl hooting...........You can localize the noise by using a rubber hose as a stethoscope. Have a friend help. She can move one end of the hose to where the suspect location is while you listen.WATCH OUT FOR MOVING PARTS.§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§REFUSE . . TO . . LOSE§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§

Have someone turn the key to start while you stand back at the pump and listen for the high pitched whine when the pump goes on. If it still makes that sound its good all the time. More than likely vacuum.

I can hear the whine of the pump when I turn it on. so it's most likely a vaccuum leak.

i had a fuel pump go un my 1997 z28...not anice feeling when youre baby is sick and you can't figure it out..anyway mine would run good when cold but it would not start when hot....well first it was somewhere in the fire maybe crank sensor you know the speel....anyway if you wanna chech you pump there is a valve on the fuel rail and when the key is in the accesory position you should have fuel pressure....just depress that valve and fuel should make a nice mess all over youre clean motor...if you wanna spend the money buy or borrow a pressure gauge and try the same thing..if you have the right pressure its not the pump....its a big job to replace the pump....(hoist needed)///