I have a 2004 F 550 and I was driving and stopped to fuel the truck and it stopped. I tried to start it but it would not start. I went to autozone and bought a new fuel pump. It started but every time I would stop, it would take awhile to start (after couple of seconds of cranking)Then I drove another 600 miles and I stopped at a mc donald and now it's not starting. there is no pressure in the fuel system when i take the key out and check the pressure. What could be the problem? If I put starting fluid, it will start (for one second)

 

someone will be along shortly to help, but stop using starting fluid unless you want to potentially replace a motor..

 

Sounds like you may have a bad fuel pressure regulator or the relay is junk. Try switching over a similar relay and see what happens

 

Pressure regulator? The one next to the second filter (on top of the engine?). What does the pressure regulator do? I am in a parking lot and don't know what to do...... Where is the relay? what does IT do? The relay is in the electrical panel?

 

Ya, if you have your.owners manual it will tell you where everything is located. I'm not sure of the placement of the fuel pressure regulator. It regulates the pressure ofuel under certain conditions like starting and WOT

 

I just noticed you put 550, so I'm guessing you have a diesel?

 

Yes it's a 6.0 diesel. The worst ever made by Ford: 04, 05, 06, 07 . Actually they are international engines. But I replaced the fuel pump and there is no pressure in the system. Takes a lot of cranking to start, and sometimes it just does not start. I took the top filter out and I noticed that the fuel was going backwards inside the supply fuel and not the other line (excess). I thought that was weird.