I have a 94 f-150 single cab, it has the 302 with the dual tank set up, my back tank seems to be pumping fuel into my front tank as well as the fuel rail, after about 10 mintues it will have enough pressure to start pushing fuel passed the gas cap and out the side of the truck. not vapors, actually liquid fuel. i looked into it, and know that the switching valve could be not switching entirely, and that the one way check valves in the fuel lines could be shot. the problem is im on a students budget, so i dont have the money to spend, but i have the knowledge. i was wanting to convert it from a dual tank to a single tank system, does anyone know where i could find the parts or any instruction to somewhat follow? this is my daily driver, and i cant have it down for more then a night.

thanks for any help.
Jeremy

P.S. i can hear both front and back pumps turn on when i cycle the key.

 

you could just pull the relay for the rear fuel pump, and it won't pump anymore. Or you could bypass the switching valve entirely and just hook your front pump directly to your fuel rail

 

i have a similar problem. if i have the switch on rear it will over flow the front tank. but if i keep the switch on front, it will pump out of the front tank and somehow the rear will slowly front tank, so its almost like having a single tank and i really dont have any problems that way. its always funny to park the truck with a 1/4 tank of fuel in the front and then come out the next morning and its almost full

 

sounds like you've got some check valve problems bren

 

Yeah you have the fuel tansfer problem. Your truck does not have the a switching valve just a pump module inside each tank. To disable a tank disconnect the power at the tank so you dont accidentally empty the contents on the ground and create a fire hazard, and find some studs like those in the pic below. A couple minutes with a hacksaw and grinder and you can turn them into plugs for the fuel lines, note you will need 2 different size studs for the send and return lines. Don't simply connect the 2 ends together or you'll create a fuel delivery problem with the other tank.

 

conanski's idea is much more sound than mine. stick with his, i shoulda looked in my chiltons first to realize there is no selector valve

 

where are the check valves? are they in the diverter valve?

 

on tank filling the other tank

 

http://www.stangler.com/motorsports/...alve/index.htm
Wow, cool old post by "Mustang 5.0" huh? :)

That thing sure seems overly complicated for what it does. :/

And this by Conanski...
http://farm4.static.flickr.com/3023/...f82e2acd71.jpg
Looks like something a guy should just make and have in the tool box, to me! :)

Alvin in AZ