Oldsmobile/Buick Repair: aurora, pressure test, computor

Question
I have a 97' aurora that will not start.  I ran a scan of the computor and found several codes.  Most saying system was too lean.  So I ran a fuel pressure test and found that it was only putting out 18 psi with specs calling for 41-47 psi...other than the fuel pump being bad or the filter clogged, is there anything else it could be that would draw down the pressure, maybe the regulator?  thanks for any help..james

Answer
Hello James,
I don't know if Aurora has any rubber hose in the return line, but in older vehicles, the way to test the regulator was to pinch the return hose to block off flow.
If that increased the pressure, the regulator was allowing too much to return to the tank.

But one place the pressure can be lost is a stuck open injector, in which case, the oil in the crankcase will be over full, and diluted with gas.

Another possibility is a split in a hose inside the tank, spraying the remainder of the pressure inside the tank.

Or, the fuel pump could be worn out, and only producing 18 PSI.

Van