Follow the rail line that runs to the injectors. You will find the pressure regulator.
It is in the fuel tank.
A bad fuel pressure regulator will cause the car to stall or not run .
To change the fuel pressure regulator in a 2004 Olds Alero, first relieve the fuel system pressure by removing the fuel pump relay and starting the engine until it stalls. Disconnect the battery, then remove the fuel rail by loosening the bolts and gently pulling it away from the intake manifold. Detach the old fuel pressure regulator from the fuel rail, install the new regulator, and reassemble everything, ensuring all connections are secure. Finally, reconnect the battery and fuel pump relay, then start the engine to check for leaks.
that pump is in the fuel tank
Most GM fuel filters are under or slightly behind the driver.
It is in the fuel tank so the tank has to be dropped, tank cover unscrewed, and fuel pump extracted and replaced.
check your fuel pressure regulator, it could be leaking http://flickr.com/photos/thatguyfromcchs08/2233062257/
The voltage regulator is internal to the alternator. TechJK ------------------
Did you change the fuel filter? Have you checked the fuel pressure regulator?
A leaking fuel pressure regulator is the most common cause for a rich condition on the Olds Aurora 4.0L V8. -------------------------
Try checking the fuel pressure regulator that's what gives the engine gas and how much its hooked to a vacuum line.