Question : why does my fuel rail pressure goes to 0 psi?

[cutlass supreme FE3]

I have a 1988 2.8 MFI and recently the fuel rail pressure goes to 0 psi overnight??
Is there a one way valve or a check valve that could be faulty and not holding the pressure??
Also I'm getting engine code 54 and I have changed to a new fuel pump relay and also my oil pressure switch is only one terminal so it does not power the fuel pump when cranking.

someone said it could be my fuel pump is starting to die.

[Superdave]

your fuel pump's check valve is bad. Replace the pump

[cutlass supreme FE3]

your fuel pump's check valve is bad. Replace the pump

so replacing the pump will get rid of the code 54 as well?

[Guest]

It goes to 0 PSIG overnight?

It's fine. I've never seen ANY vehicle hold pressure for more than about an hour, most will go to 0 in less than an hour.

My car, with a brand new fuel pump, regulator, etc, holds pressure for about half an hour or so, and in that time is bleeding down on pressure the entire time.

Why do you think this is a problem?

[cutlass supreme FE3]

It goes to 0 PSIG overnight?

It's fine. I've never seen ANY vehicle hold pressure for more than about an hour, most will go to 0 in less than an hour.

My car, with a brand new fuel pump, regulator, etc, holds pressure for about half an hour or so, and in that time is bleeding down on pressure the entire time.

Why do you think this is a problem?

I'm getting a DTC 54 and replaced the fuel pump relay and oil pressure sender but still have the DTC.
It takes like two tries in the morning to start when before it took one try.

[Guest]

Well 54 is a fuel pump circuit problem, not a pressure problem.

What is likely happening is that the ECM is for some reason not receiving a 12V input signal to the "fuel pump circuit input" (I don't recall the pin number right now).

Grab a DMM, find out what pin it is (it will be a grey wire BTW) and check to see what the voltage input is, if there is voltage there. If there is good voltage ( greater than 12.6V while running), then it is an ECM problem, if it is less or no voltage there is a wiring problem.

I would also check the priming pressure, actual pressure not just that there is pressure, and take a look for any pinched fuel lines or clogged filter.

[cutlass supreme FE3]

Well 54 is a fuel pump circuit problem, not a pressure problem.

What is likely happening is that the ECM is for some reason not receiving a 12V input signal to the "fuel pump circuit input" (I don't recall the pin number right now).

Grab a DMM, find out what pin it is (it will be a grey wire BTW) and check to see what the voltage input is, if there is voltage there. If there is good voltage ( greater than 12.6V while running), then it is an ECM problem, if it is less or no voltage there is a wiring problem.

I would also check the priming pressure, actual pressure not just that there is pressure, and take a look for any pinched fuel lines or clogged filter.

I get this erractic up and down idling