I have an 82 F100 with dual tanks. When I bought the truck the previous owner warned me that they were only using the rear tank. This truck has a electric valve to switch between the tanks.

Well I just had to see if I could get both tanks working so I topped off the front tank with gas and added a bottle of STP just in case there was water in it. Sure enough when I switch to the front tank while the truck is running it eventually shuts down after a minute or so. When I switch back to the rear tank it will crank back up after pumping the accelerator a few times. When I make the switch from rear to front tank, the fuel gauge changes to "FULL" so I assume it is picking up the reading from the front tank.

So something is happening when I flip the switch on the dash. Before I start taking the fuel system apart, does anyone have any suggestions or experience? I figured the line is plugged or the valve does not make a complete switch. Another person at work suggested that I make the switch to the front tank before I start it to see if that helps, but I have yet to try that yet.

Thanks, Steve

 

when i first bought my truck the selector valve went south on the 2 hour drive home, yeah that sucked. but i just went to the auto parts store and got a new one, was about 15-20 bucks, just sounds like you need to get a new one of those and you will be fine.

1977 F250 460
C6 Hedman Headers
Dual 40 series
edelbrock performer
holley 4160
msd 6a and blaster coil

 

I would do some electrical testing first. See where you have power and where you don't. Saves money and fixes problem first time.
Robert
1972 F-100
86 5.0L w/ AOD

 

Thanks to everyone I finally got both tanks working. I had assumed that my switch was bad, but after taking advice from the message boards I yanked the lines off the switch and had my son flip the dash switch a few times and tested it with low pressure air per the Haynes Book. The switch was fine.

After reading other posts on rubber fuel lines, I found there was a cracked rubber line going into the front tank. The line was covered with dirt and crud and probably would not have seen it with a visual inspection. With the lines off the switch, I blew low pressure air back towrd the tank and sure enough I heard it hissing on the top of the tank. With some new fuel line and 10 minutes of work, that sucker was ready to use!

It feels good to have 38 gallons ready to use! Thanks to all for their posts on this topic!