Today I peeked under my 96 f150 to look for a way to bleed out the front tank. When I bought the truck it had an X over that gas cover, and when choosing it for fuel the truck runs horribly. I am assuming it has water in it and such.

I noticed that it seemed to be leaking from where the filler hose enters the tank, and upon opening the gas cap had a ton of fuel (which smelled off, perhaps watered down) pour all over me. I am not sure what exactly happened or is happening.. but what would equate with the backed up pressure in this tank?

Theres no way fuel from tank 2 would enter back into tank one right? This is a retarded question huh?

 

Yes it will and that is what is happening.
You have a bad FDM aka fuel pump in the front (#2) tank.

 

Help me process this here. I am a newb.

How can I simply fix this so that I can make use of tank 2, and deal with tank 1 when I got some time and extra bucks without it trying to re-feed tank 1?

I had assumed they were 2 seperate tanks, both pumping off into independent lines

Is the contaiminated gas in tank 1 still circulating the system despite the dash switch being on "rear"

Is there an easy way to resolve this whole issue?

 

There is only 1 way to fix this, drop the rear tank and plug the two lines. Eventually you will need to drop the front tank and replace the FDM but that can be delayed.



There are 2 separate tanks but they pump into common lines with no check valves of any type.. those are contained within the FDM modules inside the tank.. hence why those have to be changed to stop the crossflow problem.

 

Gotcha...

So as it sits now should I assume whatever I add to tank 2 is pouring into tank 1, and both of which (if tank 1 is infact contaminated) are pumping into the engine?

Worst case scenario is what here provided the gas in tank 1 isn't actually bad, just the pump.

 

Not quite. When you use tank 2 some fuel is being pumped into tank 1. Nothing will come out of tank 1, so even if the gas is contaminated you don't need to worry about it getting into the engine.


However, since you are pumping gas into tank 1 and not taking any out, it will overfill and will leak out. So you can't really operate it like that, at least for long.

 

Ok this was a bit more like what I had in mind.

Looks like I'll be dropping the tanks and plugging those lines or atleast tossing in a new fuel pump in tank 1

SIGH I hate toying with gas