2005 F250TURD stumped....

[Tbccolley]

Have a 2005 f250TURD with fuel issues. Would not idle, changed both pumps and cleaned the filter inside the VST or whatever it’s called. Ran fine all winter.
Now it keeps dying again. Changed filters, primer bulb, blew out hoses, seems to be losing prime as the bulb isn’t hard when it dies. I can pump on it and get up to about 4500 rpms for about 20 secs and she dies
Kept blowing the fuse for the fuel Pump on the outside, found a loose ground and tightened but still having issues.

Only thing I can think of is I already burned through those pumps, but that seems quick for 6 months

[99yam40]

if you cannot keep enough fuel in the VST to keep that pump cooled and lubricated it can cause problems.
you do know that fuel runs through that electric motor to cool and lube it right?

But you need to find out why the VST is not staying full of fuel.

sucking air maybe, '
if there was a restriction on the suction side of the lift pump the bulb would flatten out and you would not be able to pump the bulb if it was flat already.
lift pump not pumping when it should, or maybe too much fuel being recycled ( is there even a recycle/relief valve on that lift pump to VST?

[Tbccolley]

I’m not sure about the relief, this is my first motor to work on, I’m currently out of town for another week and a half. Is there a certain way to bleed all the air out of that fuel system?

[99yam40]

it there is a leak on the suction side of the lift pump,( between the pump and the fuel tank) instead of leaking fuel out it will be sucking air in.
all connections could be a problem, including the filter

[Tbccolley]

The filter on the front of the motor with the red ring doesn’t run out of fuel

[panasonic]

Try running off a portable tank.

[Tbccolley]

I tried that too with ethanol free and no difference

[TownsendsFJR1300]

The filter on the front of the motor with the red ring doesn’t run out of fuel

If the cup is NOT fully seated (they tend to expand and can be very hard to seat fully with age) it will show fuel in the cup but STILL SUCK air.

Seal #9 has to be fully seated/sealing (been there done that on my F150- The plastic nut was tight but the cup was NOT seated fully..)

Just confirm the cup IS seated, no tears in that o-ring..

Might want to check the seal on any aftermarket, fuel filter assemblies, again for tears, etc..



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[Tbccolley]

I’ll have to check that, because I can’t find a leak anywhere but I have not checked that

[Tbccolley]

I’ll have to check that, because I can’t find a leak anywhere but I have not checked that

[oldmako69]

Towns gave you good advice. That cup can be persnickety to seal. A leak there can dork up the works.