Where did the Gas go ?

[MrWizard]

Apparently there is a clog in the fuel pickup in the tank and or the In Tank Pump has finally gone to pieces,
Last year I installed an external inline pump on the frame
Right now little too no fuel is reaching this pump,
In a bid to move the RV to another location close by, I connected the input of this external pump to a gas can "hillbilly style", And pulled the power fuse of the OEM in the tank pump
It started and ran, but it pumped 3 gallons of gas from the can in a few minutes, going less than one mile,
No fuel was spilled, No external leaks, No fuel on the frame, or the engine, or the ground/street, No fumes, No smell,

Is it possible the fuel somehow went thru the return
lines into the tank ?
Or
Maybe dumped into the engine by a blown open injector ?

1996 Ford 460, F53 RV chassis

[MrWizard]

Btw. Quick short update
a test, with the pump in the rear, and using the 'generators' fuel pickup the engine stated, ran, no problems, pushing fuel toward the engine, works better than sucking it forward
Having a Tag axle makes for headaches trying to attach to the OEM line this far back

[MrWizard]

Yes some did
That scenario doesn't work with this RV construction and floor plan
Cutting a hole in my floor, above the tank
Would open into the basement area where the black and gray tanks are, I would need to cut a hole in that floor also, provided the plumbing was not in the way

[Stim]

Didn't some people cut a hole in the floor over the tank for access to the fuel pump instead of dropping the tank?
Then put in a hatch to cover it.

[MrWizard]

Yeah I know the generator pickup is at a differing level in the tank, and a smaller diameter line, but it might help In diagnosis and decision making
I wasn't thinking about the pump having a check valve
There goes that idea
Thanks for reminding me

[RLS7201]

MrWizard wrote:
I'm cashed strapped , don't have a $1000 too drop the 70+ gallon tank and install a new in tank pump
( there goes the stimulus check , IF it ever arrives )

I'm going to try blowing compressed air back thru the main fuel line,
I might even try a test, connecting to The generator pickup tube,
My biggest priority until now, was to get airlifts installed at the drive axle

There is a check valve in the in-tank fuel pump that helps hold fuel line pressure when the engine is turned off. You should not be able to blow back into the fuel tank through the engine fuel line. The generator fuel line is a totally different fuel pick up delivery system.

Richard

[MrWizard]

New fuel pressure regulator Spring 2019,
Before I installed the external fuel pump,
At least that seems to be doing its job

I did not know the fuel return was connected at the pressure regulator,
The chassis manual I have does not make that clear,
At least for me, with my lack of experience with these systems,
It does not show the system as a diagram,
It has drawings of component locations
You have to already know how it works, and what you are looking for and looking at,
Really appreciate the help I get here

[MrWizard]

I'm cashed strapped , don't have a $1000 too drop the 70+ gallon tank and install a new in tank pump
( there goes the stimulus check , IF it ever arrives )

I'm going to try blowing compressed air back thru the main fuel line,
I might even try a test, connecting to The generator pickup tube,
My biggest priority until now, was to get airlifts installed at the drive axle

[RLS7201]

On you old in tank fuel pump is a sock that is probably choked with junk from the tank.
On the left side fuel rail is the fuel pressure regulator that sent the excess fuel back to the OEM tank.

Richard

[wildmanbaker]

Pretty sure the 96 is a multi-port fuel injection system, and uses an high pressure in tank fuel pump. Still, check the oil just for grins and giggles.

[wa8yxm]

midnightsadie wrote:
X2 but i,d check the oil level.

DItto on that

If you have an older engine with a cam driven fuel pump. and the diaphragm on the pump gets religion (Becomes holy. ok holey) the gas goes into the oil pan.

[dodge_guy]

A 96 Ford is a return system. So yes it got pumped back to the tank. Time to fix it properly. Install a new intake pump with a new pickup. And a new filter.

[Bruce_Brown]

I'm thinking return line or back fed through the in-tank pump.

[midnightsadie]

X2 but i,d check the oil level.

[georgelesley]

If the engine ran normally I would say the return line took it to the tank. That is what happens normally when excess fuel is provided by the fuel pump. Somewhere in the fuel injection system probably near the end of the fuel rails there will be a pressure regulator that directs the fuel in excess of what the injectors are demanding back to the main tank.