Cadillac Repair: fuel pressure, cadillac seville, check valve

Question
I have a 96 Cadillac Seville that after sitting for a week, will not start unless I spray starting fluid into the air strem.  It then starts and runs fine.  If I use the car everyday, I do not have this problem, only after it sits for several days.  Is there some kind of check valve to keepthe fuel from going back to the tank? What else could be the problm?

Answer
Try turning the ignition to the ON position, DO NOT TRY AND START THE CAR) and back to the OFF position 3 times and then see if it starts right up.

Probably a small leak in the fuel pump check valve that I would not be to concerned about right now.

tom