Cadillac Repair: 1994 cadillac fleetwood, oil pressure switch, 1994 cadillac fleetwood

Question
I have a 1994 cadillac fleetwood.  It ran great for the first week after I bought i and one day it just died while driving.  The gas pedal went all the way to the floor but speed droped until i had to pull over because car had died.  The car will start everytime you crank it but it will imediately die.  Someone already checked the fuel pump and they said it had enough pressure.  Do you have any suggestions?
Thank you

Answer
As soon as you turn ON the ignition switch to start the engine a 2 second ONLY battery voltage signal is sent from the computer to the fuel pump relay and from the relay back to the fuel pump in the fuel tank. This runs the fuel pump for ONLY 2 seconds of which pressurizes the fuel system in preparation to start the engine.

Once the engine starts, The computer BYPASSES the fuel pump relay and  sends constant contionous battery voltage from the computer to the oil pressure switch of which is now CLOSED because the oil pressure is UP because the engine is running. Therefore the battery voltage flows thru the oil pressure switch back to the fuel pump to run the fuel pump constantly until you turn OFF the engine. If the oil pressure light remains ON after the car starts the most likely suspect would be to replace the oil pressure switch,.