Originally Posted by Mike1

Do you have vacuum on the line going to the MAP? Do you have a hand vac you can hook up to the MAP? I haven't had to mess with a ford one yet, but I remember my daughters 95 Toyota having issues, and she was getting low vacuum on the line for the MAP, I hooked up my hand vac to it and slowly pulled about 22 pounds on the map, the car started running very smooth, when I released the pressure it ran rough again. I rerouted the vacuum temporarily so it would pull harder, it was a quick fix, but ultimately had to pay the $200 for a new MAP sensor. If you have any cracks in the vacuum lines at all, it takes away from the whole system and it's suggested that all the rubber lines should be changed every 8 to 10 years.

Originally Posted by annaleigh

So at the time you checked the fuel pressure and were only getting 28psi, you had already changed all 3 fuel pumps, filter, and FPR?
If its not 32 to 35 psi then you still have a fuel problem.
Did you take the vacuum line off of the FPR while it was running? The pressure should have gone up to 39-45psi. Did you check to see if you have any vacuum on the line vacuum going to the FPR? If you don't have vacuum on the vacuum line going to the FPR (and it was connected) then the pressure should have read a higher psi.

With the fuel pressure gauge connected and the engine not running, if you cycle the ignition switch from off to run 3 or 4 times, the fuel pressure should build up to over 30 psi and stay there. Have you tried that?
If the fuel pressure immediately drops off then you have either a leak, bad fuel pump, bad fuel pressure regulator, leaking injectors, or injectors being held open when they shouldn't be.

The Ford high pressure fuel pump is capable of pumping over 21 GPH at a working pressure of 39 PSI and has a internal over pressure relief valve set at 123 PSI should the fuel become restricted. So again if everything is working properly, you should have no problem building up 32 psi... I suspect that you have problems with your injectors...

On the 5.0 and 5.8 engines you have to remove the upper plenum to remove the injectors with the fuel rail.. I believe on the 7,5 engine that you can loosen the fuel rail and pull the injectors out of the lower intake without removing the plenum. If so then you could pull the injectors out leaving them connected to the fuel rail and cycle the ignition switch and look for any injectors that might be spraying out fuel. You might want to put a container like a vegetable can or something under each injector so that if one is leaking, you can catch the fuel.

Originally Posted by Mike1

Do you have vacuum on the line going to the MAP? Do you have a hand vac you can hook up to the MAP? I haven't had to mess with a ford one yet, but I remember my daughters 95 Toyota having issues, and she was getting low vacuum on the line for the MAP, I hooked up my hand vac to it and slowly pulled about 22 pounds on the map, the car started running very smooth, when I released the pressure it ran rough again. I rerouted the vacuum temporarily so it would pull harder, it was a quick fix, but ultimately had to pay the $200 for a new MAP sensor. If you have any cracks in the vacuum lines at all, it takes away from the whole system and it's suggested that all the rubber lines should be changed every 8 to 10 years.

Originally Posted by Mike1

I know you said you unplugged the MAP, but did you check the voltage going to it? If you changed it with 3 others and there's no difference, maybe its a power issue?

Originally Posted by Maillemaker

What was the resolution here?