I think my fuel pump is going bad

[Jcbaldwin]

Hi there I have a 1994 Mazda Navajo a.k.a. Ford explorer and seem to have a little problem. My truck starts right up but when it is running it will run smooth for a little but then do a rough idle. Also when I press on the gas it stalls out on me. Another thing is that my fuel pump is making a whining noise that is in sync with the engine running, when it idles rough the fuel pumps whine becomes almost pulsating. Does this sound like a bad fuel pump. Oh I also have replaced my fuel pump too when it started but it didn't help at all. Oh by the way the check engine light comes on eventually

 

[1Aauto]

Welcome to the site. Usually fuel pumps will become loud then they are starting to become worn out. You may want to take a look at it.

 

[Jcbaldwin]

Thank you the whine noise is pretty kud when I turn the key and it gets the pump running and when the truck is

 

[Jcbaldwin]

Okay I did a fuel pressure text and just cranking only got 40 psi and when it was running it bounced between 30-35 psi. So I changed the fuel pressure relay and now it starts up but then immedietly shuts down like its not getting pressure or gas..someone please help me