1991 ford van fuel tank bypass, looking for info

[AdRock]

I've got a dual tank 91 e150 and I'm not using the rear fuel tank anymore. But it seems that when using the front tank some of the fuel is going back into the empty rear tank. I thought the mileage was just shitty but the rear tank has been filled up with gas from the front tank.

Is there a diverted I can bypass or is it just a one way valve in the rear pump that has failed? I basically just want to completely take the rear tank out of the equation, but I'd don't want to cut and block off the rear lines. Anyone have any suggestions ?

[Stangs 4 Life]

I believe your problem is caused by the return fuel not going back to the tank from where it was pumped. Probably the easiest fix is to return the rear tank to normal operation. ie Fix the fuel pump

When these ford trucks dual fuel systems were everywhere, it was not uncommon to see a stain on the side of a vehicle. This was because the return fuel would fill and then pressurize the non-operational tank forcing gasoline past the filler cap.

[JC316]

In 91 there is a dual function reservoir and check valves that goes bad. You don't have to change the fuel pump in those years

[AdRock]

I kinda figured that might be the case. I also found a recall that addressed the cross fill issue. I'm going to call the dealer and see if it was ever done.

[SMEGMA STENCH]

I believe your problem is caused by owning a 1991 ford van.

[Pro88LX]

I believe your problem is caused by owning a 1991 ford van.

/thread?

[JimD]

I believe your problem is caused by owning a 1991 ford van.

LOl no shit

[Diabolic]

Go to the junk yard and remove the feed and return lines at the tank off another F150, 250, bronco, or van. Just cut them off or take the entire module with you. Fill both tubes with solder. Plug into stock fuel lines. No leaks, no hacking, and when or if you ever fix or reinstall the rear tank just unclip the plugs you made.