Is it possible that I could have 15psi when key is turned and pump turns on, then also doesn't move more than 1lb when the truck starts and/or giving it throttle? It's a new harbor freight oil pressure gauge, maybe it's junk? It also drops to 0 when I turn the truck off, shouldn't it hold pressure at least for a bit? The fuel bowl is draining after 20-30 minutes. I started looking into this when the truck died on me and wouldn't start. A week later it is starting, running (I haven't down anything to it) and seems back to normal but haven't taken it on the road.

 

Do you have a compressor with a regulator? If so turn it down to 65 psi and put air to your gauge to verify it is functional.
When you turn the key OFF, yes it will almost immediately drop the pressure down to 0.
Also yes it is possible to only be making 15 psi. but that is BAD. It should be around 65 at idle and no less than 45 at WOT.

 

Thanks, not sure why I didn't think of testing it with an air compressor. I will try that.

 

In your previous thread, you mentioned 10k miles on the fuel filters (according to previous owner) and I assume you don't know if they are OEM or not.

After verifying the pressure gauge, then this is where I would go next ....

Quite frankly, in all used vehicle purchases, the first thing to do is fluids and filters IMO.

 

Yeah, I agree about filters and fluids, I guess I was just curious the pressure before and after. I got my Motorcraft filters yesterday but haven't changed them. I haven't actually met back to pay the last bit and get the title for the Excursion. Planning to keep it, just want it to all be sorted out before I spend a bunch more money/time. Also planning to start using T6 when I do the oil. There's a slow leak I didn't notice on the steering gear box and oil all around the rear of the engine... I got a good deal but I'm going to have to do a little more negotiating. It's already caused me too many headaches.

 

No, it should drop to zero fairly quickly. There's a bleed hole at the top of the secondary filter housing that bypasses the regulator, so there's no way for the system to hold pressure.

This was an issue on pre-05 motors, the fuel lines where changed to a banjo fitting and a trap to stop this exact issue. Probably still worth getting a blue spring kit and resealing the plunger to see if you can stop it:
http://www.riffraffdiesel.com/ford-f...ue-spring-kit/

 

The truck is an 03.... is it a problem that the fuel bowl drains or a reason it's bad for things?

It is supposed to have the blue spring mod done already but I don't know where exactly that is yet to verify. Is it possible the blue spring needs replaced?

 

The fuel bowl can drain for bad reasons, or because something is leaking in the regulator housing. There's no way to know with it being an '03 because the fuel line design, but if it runs normally then odds are it's not really at 15psi and the bowl draining is a seal.

It doesn't matter if the spring was upgraded in the past or not; the spring isn't the part of the kit you need necessarily, it's the seals that it comes with. At that point just put the new spring in anyways.

Read post #3:
https://www.ford-trucks.com/forums/1...r-housing.html

 

I'll make this clarification since I was the one who suggested using the oil pressure gauge for fuel pressure monitoring. Once you get the hose connected to your pressure port beneath the secondary filter, it is crucial to remove the air from the hose in order to get an accurate reading. This can be done by removing the gauge from opposite end of the hose and running the fuel pump until a steady stream of fuel, free of bubbles and foaming runs from the hose. Hope this helps.

 

Thanks Ruslan, I will definitely bleed the line on the gauge. I hope to have time to change the filters tonight and check it all again. I should also note there was a very slow dribble of fuel coming from the port I attached the gauge to. All I had was white teflon tape on the nipple, I snugged it but not sure what else I can do, I don't want to crank it too much. I figure it would affect my PSI some but didn't think 50 PSI worth. When I saw it, I loosened and the drip got faster but PSI didn't change. Then I tightened it (getting a drip about every 5-8 seconds) and no change in PSI. When fuel pump comes on after turning key it goes right to 15, starting and revving it doesn't budge... seemed strange to me, hopefully bleeding helps.

TexasTech, would getting the blue spring kit (seals) be the first thing you would look at/try? The PO has only had the truck 3 years and told me he did the kit (not sure when but it's no more than 3 years old). He also did all 8 injectors (oem) 2000 miles ago but I don't think did the hfcm...

 

You don't want to use any type of tape in the fuel system.
That adaptor should have an O-ring on the front for sealing and
that should be all. The slide away from the fuel bowl should
be sealed with diesel resistant paste. A tiny amount will do the
job. You don't want any on the face of the fitting.

The issue with any of the tape stuff is it gets places where you
don't want it and can be impossible to remove in some spots.
Also it does not dissolve and can block ports.

 

Hopefully I didn't get any tape in the system. I made sure there was none at the very tip of the adapter I threaded in... I originally put an oring on but the adapter is a tapered at the back up the threads and it worked its way out, pushed and spread around the outside of the fuel bowl assembly so no real way to use an oring with that adapter. I could attempt to file a groove like the plug has to keep the oring in place, otherwise with this fitting I don't know a way to do anything different.

 

FGT 6896 Ford 6.0L High Pressure Oil Rail Adapters Leak Test Kit (Fuel Rail) New | eBay
The adaptor that you need with an O-ring is in this set.
The one you need has the relief so it will clear the edge of the bowl.

 

The first thing is to get a gauge that works hooked up correctly. I wouldn't mess around with a HF mechanical gauge, buy one for a permanent installation:
https://www.ford-trucks.com/forums/1...l#post12858489

Then I'd do several things. Pull the secondary filter and see how fast the bowl drains. Do a bubble test second just because you're all set up for it already. Then if that passes I'd reseal the regulator. All that's predicated on it actually not running at 15psi, if it is then the spring kit is first.
https://www.ford-trucks.com/forums/1...tor-leaks.html
https://www.ford-trucks.com/forums/1...ue-spring.html

Anthony (run6.0run) has a five part video series on the test:

 

Thanks! If I keep the truck (which I plan to but need to renegotiate with the PO) one if the first mods I want is a permanent fuel pressure gauge... actually one with an alarm is what I want to find.

I wasn't able to do anything on the truck last night so hoping tonight I can bleed the gauge line and verify with an air compressor the gauge is at least someone accurate. I will also change the filters and do the bubble test.