fuel pressure?

What is the fuel pressure suppose to be on a 93 Deville with a 4.9 has PFI injectors I am getting 36 psi at idle and it backfires bad and lack of power!

Any help will be greatly appreciated!!

36 is too low 44 is about right. Could be a blocked fuel filter, bad press. reg. or bad fp.

36 is too low 44 is about right. Could be a blocked fuel filter, bad press. reg. or bad fp.
I am going to change the filter again also when I turn the key on I only get about 3 psi.Thanks for your help max wedge i will find out if the next filter helps.

crewdawg 692!

Pinch off the return line from the fuel rail, see if the pressure goes to 44 or beyond, BTW that fuel must be the high pressure type, very important. Also try removing the vacuum hose from the regulator, see if it jumps up, and check for signs of fuel in the hose.