I have air getting into the supply line, you can watch the pump quick empty the filter then foamy fuel starts coming into the pre filter.
So the other day i stop and throw 6 gallons in the tank, 3 or 4 miles later i feel the truck start shaking, worse and worse till eventually it wouldnt run. Diagnose it to be not getting fuel.
Throw in a new main motorcraft fuel filter, its been about 8k miles, old filter looked excellent, fuel drained from bowl into clear container, fuel also looks excellent, no debris to speak of, no water, new bosch lift pump, new prepump filter install i did exactly as skyskijason details in post 25 and 26 here: https://www.ford-trucks.com/forums/1388668-pre-pump-filter-options-2.html
I suspect the Hutch mod i did 2 years ago is to blame right now (maybe came lose???) No i did not install a pre filter with the hutch mod. All other fuel and return lines perfectly fine and dry all the way to the tank.
I have never had any reason to suspect a problem, quite the opposite, leave it sit for weeks, starts right up perfect, no fuel leaks, only oil leak is the dipstick...
The only other oddity i noted was no fuel siphoning from the supply line once i removed the pump...

Am i missing something somewhere or am i definitely dropping the tank?

 

Hey diesel4lyfe , for clarity did you just recently install the small plastic pre pump filter or has it been on there since the hutch mod? Being that everything pre pump is on a suction you usually won't see leaks( unless something is really loose), it will usually just suck in a bunch of air. Did you try double clamping everything? Others have had better luck with the small plastic filters but I was not as fortunate, just couldn't keep the air out. Ended up going with a racor PS 120 with barbed fittings and it has worked excellent.

 

No pre-filter until today, put the napa 3972 in, same as wix 33972. I wish i had one before now, probably would have saved me 140 bucks at napa.

 

You might try rigging up a fuel line into a five gallon container and see how she acts , this will tell you if you need to drop the tank. Just run a hose off the inlet of your wix filter down into a jug to see how it runs and if your still getting a ton of air in the fuel.

 

People may accuse me of sounding like a broken record, but this is the absolute fail safe cure for any air getting into the fuel. Laws of nature dictate that it's a lot easier to push a fluid than to try and pull it towards the fuel pump.

 

And I'm still running the same pump ten years later with zero indications of any trouble.

 

X2 on the in tank pump, pretty much impossible to suck air if the pump is bathing in fuel. Had mine in the drink for 2+ year's now. The stock pumps work just fine in tank also. Had my factory original pump in there for 8-9 months without issue. It just finally got to weak to maintain 60+ psi at WOT. Can't blame it after nearly 22 years and over 200k.

For your immediate troubles, I hate to suggest it but a full or at least 1/2 or better tank would confirm or deny the in tank plumbing as your source.

 

So i got the tank on the ground and pulled the sending unit, i cant find any reason for the air, every inch of every line looks perfectly fine, blowing into the lines produces no pressure loss. There may have been some wetness on top of the tank near the QD fittings, but i cant say for certain since things got dripped on when i disconnected the lines. So at this point im going to eliminate the Quick disconnect fittings and use rubber.

So wait, you put your frame rail pump inside the tank??

 

Yes I did. Worked just fine, probably helped it in the end. Less strain not having to lift the fuel up out of the tank and through another 5-6' of tubing/hose to prime. I was researching in tank diesel lift pumps and not having much luck until I found a few references to the Bosch 044. When I got a look at it I couldn't help but notice the similarities between it and our factory units. So I decided if that one can swim I bet mine can too. Figured I didn't have much to lose since mine was already showing signs of fatigue.

 

Putting the fuel pump inside the tank doesn't do it any harm at all. It's already pulling fuel through itself anyway, due to how it's designed. Putting it in the drink just changes where it's located and in doing so, also completely eliminates any chance of air being drawn into the fuel stream on the inlet side of the pump. Every inch of the fuel supply plumbing is now under positive pressure, not negative, which is where the air is getting introduced.

 

Well finally mystery solved!
DEBRIS in the line. One of those round fibery, foamy, cottony, bottle cab seals probably off a bottle of fuel treatment, and a large chunk of rust was stuck in the supply line right at the point before the pump where it transitions from metal to plastic. The line actually has a rolled tip on it that had caught the debris.

Now i get to drive it to where shes gonna be parked till i fix the rusted out fuel tank mount crossmember, carrier bearing mount cross member, and spare tire carrier, and find a new bed.

 

Nice, Nancy Drew'd the hell out of that one. I kid, but truthfully nice catch. Good to hear it's fixed, sucks to hear it's getting parked. Not for long I hope. Really only 2 things kill engines in my opinion, heat and sitting.

 

lol like a squirrel tryin to find a nut! How crazy is that, of all the things to end up in the line. And the factory plastic screen is still on the foot at the bottom of the tank, how it managed to get in the line is beyond me.