Does my 2000 e320 have Fuel Pressure Regulator?
 

Because of hard starts & fuel rail pressure immediately dropping to zero when the car is shut off, it appears my 2000 e320 wagon has an internal fuel leak.
I see plenty of Fuel Pressure Regulator (FPR) replacement tutorials for older & newer e320s, but none for year 2000. O'Reilly's lists no replacement part for a 2000 e320 Fuel Pressure Regulator. Is it possible the 2000 e320 has no FPR?
I've already replaced the fuel pump & filter. Please advise. Thanks, C.

Yes your car has a fuel pressure regulator, its built into the fuel filter. (your car will have a 4 hose filter rather than 2 hose)

When you replace it make sure that its either a genuine mercedes or Bosch filter. The others have a bad tendency to either squeal or act stupid.

The filter is bolted to the floor of the car like the W124 and requires clic lock pliers to undo - if you dont have those pliers you can tear off the clamps and use screw type fuel injection hose clamps as replacement.

Thank you.