fuel pressure


i have a question with residual fuel pressure. after running engine, and shut it off i noticed that my fuel pressure drops from 42 to zero, almost instantaneous. do the fuel pumps have an check valve to prevent residual pressure or do i have to remove the fuel rail and check for stuck open injectors. or is it normal on these cars? thanks
The pump has a check valve.

Bad injectors will show themselves as a puff of black smoke on start up from fuel bleeding down a runner.. meaning overly rich. If the pressure goes down to zero.. you start car and its clean.. bad fuel pump.

can also be a bad fuel pressure regulator