for those with dual tanks

[sbx22]

Do any of you experience one tank gulping gas more than the other? When the switch is on for the passenger side tank, it"sips" the gas. But when it's selected for the driver's side, for some reason it feels like it "gulps" twice as much as the passenger side. I know both tanks are the same size, and I've swapped out both of the fuel sending units. All rubber fuel lines were replaced.

[bake74]

     There is no physical reason why one side should use more gas than the other considering the fuel pump is drawing from both sides.
     I would look for some kind of leak you have not noticed or somehow evaporation from the one side.

[87 V20]

R u sure that the sender just aint readin right?? just my 2 cents.

[bd]

Fill both tanks.  Drive the truck 100 miles on either tank the way would normally.  Switch tanks and drive the truck another 100 miles the way you would normally.  Then fill both tanks and compare.  That will tell you whether there's a discrepancy in consumption between tanks.

[sbx22]

Thanks for the replies. I will just have to do an experiment with numbers, just wanted to throw it out if anyone has run into this themselves. Also, I have new sending units for both tanks now, and even with the old units, they did the same thing.

[Irish_Alley]

had a similar problem on a ford, the tank selector valve wasnt returning the fuel from the same tank it was drawing from. if it was on the left side it would put the return into the right side. if it was on the right side it would put it on the right side. he only noticed it cause the engine was running rich and cutting off. when he was pulling from the left side it over filled the left side and the fuel had nowhere to go except back to the engine.

[jarhead76]

my left tank reads full all the time and i think my right tank is lying to me about how much gas is in it. but if some one knew how to fix it i would be glad to try and help figure out your question.

[Irish_Alley]

mac cant really help you on your topic of my head. but start a new post about it so we dont have two different problems on the same post

[Andyman]

I should have read this first! I just purchased a '77 c-30 converted into a dump truck, and after I got it home and rebuilt the carb fuel started pouring out of the passenger (original) gas tank. After much deliberate investigation, I discovered that the fuel switch is wired so that the fuel was coming out of the driver tank, and excess fuel from the pump was returning to the passenger side. Because it's nearly impossible to troubleshoot the valve and figure out what lines do when going into the passenger side, I just routed the return directly back to the driver tank and removed the valve. Then I hooked up an electric pump and filled the driver tank with gas from the other. I think I pumped about 30 gallons before it was filled, enough to stop worrying about fuel spilling out the other side. Nice thing about all this, is the truck came with a lot of free fuel! I don't know how much fuel the original tank holds, but its a very, big tank. The funny thing I noticed, is that it does not matter which of the two hoses I pump the fuel from that is connected to the other tank. Apparently, at least so far... both the supply and return lines are at the same depth. I don't plan to use the original tank because it can't be fueled without raising the dump bed, and the driver tank holds about 50 gallons- enough for me to run around town.