1990 Ford F150 dual fuel tanks

Asked by Nov 21, 2016 at 02:50 PM about the 1990 Ford F-150 XLT Lariat LB

Question type: Maintenance & Repair

I just bought a 1990 f150 xlt lariat. Currently the truck is pulling from the
rear gas tank. When I switch to the forward tank, the needle on the gas
gauge gets pinned way past full and the truck dies, as if it just ran out of
gas. When I switch back to rear tank, truck runs fine.  Does anyone have
any ideas what could be wrong with forward tank. It appears as if the
selector switch is functioning fine.

5 Answers

It seems that it has a Fuel pump issue. In all actuallity, it seems as though the pump may of been taken out or completely unhooked from functioning. If the pump for tank 1 is disconnected from power, the needle will jump all the way up!!


Check the wiring plug to make sure tank front tank is connected, if it is, you'll have to remove it and inspect the fuel pump assy

Thanks for your quick response Thomas and lrodri911. I'll check the fuel pump connection. Is it mounted along the frame rail?

I have a similar issue and the problem isnt the fuel pump its the selector valve getting stuck it dumps all the fuel from the rear tabk into the front causing it to over fill be warned if u try and loosen the front fuel pump or which ever is pinned over full about 3 gallons of pressurized fuel will spew all over you i took a shower in gas .... be warned if your a male and your tank sprays you your area down below will burn and smell of gas for about two weeks. Anyways im trying to locate a way to make it run off the front tank only . Any clues ???

And dont drive with it pressurizing the front tank if the seals fail while driving it sprays on hot exaust and causing explosion and or fire.this is per a certified ford mechanic

Your Answer


Looking for a Used F-150 in your area?

CarGurus has 195,941 nationwide F-150 listings starting at $1,500.


Ford F-150 Experts

  • #1
  • #2
  • #3
View All

Related Models For Sale

Used GMC Sierra 1500
972 Great Deals out of 65,610 listings starting at $1,975
Used Ford Mustang
540 Great Deals out of 35,434 listings starting at $1,200
Used Ford F-250
465 listings starting at $2,995
Used Ford Ranger
139 Great Deals out of 5,359 listings starting at $800

Used Cars For Sale

2018 Ford F-150 For Sale
69,247 listings starting at $20,867
2017 Ford F-150 For Sale
129 Great Deals out of 54,680 listings starting at $14,369
2016 Ford F-150 For Sale
147 Great Deals out of 7,789 listings starting at $17,194
2015 Ford F-150 For Sale
357 Great Deals out of 11,313 listings starting at $14,998
2014 Ford F-150 For Sale
506 Great Deals out of 14,228 listings starting at $9,900

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.