I posted this in the van section but it's quiet over there. I'm working on a 2003 Ford E250 with a 5.4. It's running bad and has a misfire, and I think it may be the Fuel Regulator. So, I was gonna go rent the fuel tester gauge and test it but I need to know what it's supposed to be at. AND, any tips on how to change the regulator? It looks odd. I was gonna change the spark plugs but gave up. I'm used to old engines haha.

 

Fuel pressure 03-45 psi regulated and 40-50psi with vacuum line disconnected.The regulator has a snap ring in the face of it(fender side.)
You need to get the Van scanned for codes if you haven't already.Even if the check engine light is off it might show you a pending code for the miss.It sometimes takes a long time for the pcm to decide it is a miss fire.Most common cause of a miss fire is a plug or a coil.
These specs are for f150 5.4 pickups but I would think the e250 should be the same.

 

Do you mean "30-45" or is it really 03? And I will be having it scanned again. It's my neighbors and he had it scanned but he didn't write them down. It was a misfire in a couple cylinders and he was told it may be plugs so he bought some. I didn't change them because I can't get to them. I figured testing the pressure is free and easy

 

I agree with Vaper should have it scanned, and how does it run bad? sluggish, shaking in idle, drive, hard starting? How many miles? original plugs? etc

 

It was scanned. BUT the owner isn't familiar with auto repair and didn't write them down. He said it was a code for a misfire in a few of the cylinders. It runs almost like an older engine would if the choke was kinda closed. It has a sulfur smell too. It bogs when you drive it. The Pressure Regulator wouldn't be hurt to just check it. I only think it's that (but I still haven't checked anything else, it's only a start) because my 5.0 in my truck did the VERY same thing and it was the fuel regulator. Honestly, he just bought the van not long ago. You'd be surprised at the things we found wrong with it. (Example: the front right shock wasn't ever bolted in at the top. It seems to have been dangling for years judged on the rust and scratches) The plugs, who knows haha. He has new ones but being in a van, I don't know how to get to them since I've never fixed these engines before. He'll be having that done somewhere else. This weekend we;ll be pulling the codes and I'll be there to write them down and I wanna test the fuel pressure. I'm not saying that the regulator IS bad, I just wanna check it. Right now it's down because of the broken lower shock mount. I was told that these have the "Coil Over Plug" set up and that a bad coil can do it too. I'm not touching that. I'm only doing what I can to help

 

Yeah it doesnt hurt to check the fuel hopefully thats it, as it has 8 COPS (coil over plug) next to each injector and the plugs are about 4 inches below each COP ,no fun to change

 

Especially in a van haha. He's already thinking about selling it once it's fixed. He never had anything done to it til recently and it's like a death trap

 

30-45 ooops typo

 

Usually around 32psi at idle, 38-40 with no vacuum to the regulator. It may just be due some plugs or have a dirty MAF. I would rescan it for codes again before bothering with the fuel pressure. If the regulator fails, it will leak fuel from the vacuum line port.