1996 Jeep Cherokee Fuel pump

According to "Chilton" manual for this vehicle, fuel pressure at rail test port should be 31 psi. Measured pressure in my Jeep is around 48 psi. In my view this would indicate a failed pressure regulator, which according to manual is built into pump for 1996 model year.
Vehicle runs OK nearly all the time and no codes are set (no check engine light). Ocassionally it will die at idle, but will restart and ususlly run OK if key left off for a few minutes.
Is 31 psi the correct fuel pressure for this vehicle and would you agree the internal fuel pressure regulator has failed in the pump? Is it possible the occasional stalling at idle could be related to the failed fuel pump internal pressure regulator or perhaps an impending failed fuel pump?
Thank you,
Ron J.