I HAVE A 1990 FORD F150 XLT LARIAT THAT I NEVER USE THE BACK TANK. I PUT SOME GAS IN IT WHEN I BOUGHT IT, BECAUSE MY UNCLE WHO SOLD IT TO ME DIDN;T REALLY KNOW IF THEY WE'RE ON THE SAME LINE AND EQUALLED OUT EACH OTHER OR NOT. I KNOW THERE'S A SWITCH FOR EACH ONE, BUT ON THE REAR TANK WHEN SWITCHED TO IT MAKE A SLIGHT HUMMING SOUND AND SHOWS IT PAST EMPTY ON GAUGE. THEY'RE SHOULD BE SOME GAS IN THERE BECAUSE I NEVER USED IT. SHOULD I JUST NOT WORRY ABOUT THE REAR TANK OR DO I NEED TO SHUT OFF ANY ELECTRICAL CONNECTIONS AND GAS LINE FROM IT.
I had same problem with a 90 f250. I unplugged the rear pump. An straight wired the switch. Gas gos bad to fast for me to use 2 tanks. An I filled it w water and antifreeze after cutting the line for extra weight. And Put a locking cap on
far as cleaning the tank. I always drop tha tank, pull the pump off, and clean with a rag and new gas.
Use a tester an make shire u have power to Gage part of pump connectn. No power its a fuse or ground issue. If u have power, bad sending unit.
I had same problem with a 90 f250. I unplugged the rear pump. An straight wired the switch. Gas gos bad to fast for me to use 2 tanks. An I filled it w water and antifreeze after cutting the line for extra weight. And Put a locking cap on
far as cleaning the tank. I always drop the tank, pull the pump off, and clean with a rag and new gas.
Use a tester an make shire u have power to Gage part of pump connection. No power its a fuse or ground issue. If u have power, bad sending unit.
im thanking theirs a fuel filter under cab on drivers side on line.
×
SOURCE: Dual tanks on 1990 Ford F150
It should not cause no problems but instead of removing the tank leave it in the truck take out all the fuel in the tank and jus discontinue use of it. This will save you alot of time and trouble and i also suggest that if anyone besides you drives this vehicle then i would put a locking gas cap on it so it cant be accessed at anytime except by you.
SOURCE: 1987 fuel level guage issue
thats funny, my 87 F250 does the same thing. At 80 bucks a sender unit I have learned to live with it even tho this is what I do for a living.
The reason fuel gauges fail is because of sulfur in fuels.
Do a search on sulfur and fuel sender units failures and you will find your complaint is the same as the masses.
SOURCE: 1987 fuel level guage issue
the gas is regulated from the switching valve you control off the dash. Check the valve to hear it switch
have a friend help you do this. it will be located under the truck between the two tanks. You may have a faultly valve or switch rattling inside changing the tanks setting also while driving which will be hard to tell
SOURCE: 1989 Ford F150 Lariat Dual tanks...rear tank is
Thet don't have a switching valve,the switch just turns on one pump or the other.
Ford dealer has a fix ,a short piece of line with a one way valve,just snaps on to both lines .simple install,just buy the part,they will know what you are talking about at the parts counter,
SOURCE: I have a 1990 Ford
Sound like your fuel tank selector valve is bad.it's located on the frame rail between the tanks and the filter.
Also, keep in mind that the rear in tank pump is bad. The dual function reservoir is mechanical. The pressure from the in tank pump switches the mechanical valves; the dual function reservoir serves two purposes:
1. Mechanical Selector valve for the tanks.
2. Holds extra fuel in the reservoir so if the gas tank is low on fuel and you go around a turn and the low pressure pump can't pump any fuel, the high pressure pump can still draw fuel from the reservoir.
Read this thread which explains how to test the in tank pumps: ford-trucks/88-5-0-no-start-fuel.
Keep us updated.
121 views
Usually answered in minutes!
I BELIEVE THAT WHAT I'LL DO--JUST LEAVE THE TANK IN THE TRUCK FOR THE EXTRA WEIGHT FOR TRACTION. HOW IS THE BEST WAY TO GET OLD GAS OUT OF REAR TANK?? I HAVN'T REALLY TRIED RUNNING IT DOWN THE ROAD WITH THE REAR TANK SWITCH ON YET BECAUSE THE FUEL GAUGE LOOKS REAL EMPTY AND MAY CLOG MY NEW FUEL FILTER I PUT IN A FEW MONTHS BACK. I WILL ALSO CHECK ON THE VALVE SOUND BETWEEN TANKS WITH A FRIEND. I KNOW BEFORE MY TIME OF OWNING THIS VEHICLE THEY HAD A COUPLE OF RECALLS ON GAS TANK TROUBLES. ONE TAN K IS PLENTY FOR FARMING AND DEER HUNTING AROUND CLOSE BY ANYHOW. BUT I WOULD LIKE TO KNOW HOW TO GET GAS OUT OF REAR TANK OR IS IT ALREADY GOT BACK INTO FRONT TANK AS A GRAVITY BALANCE EQUALIZER??--THANKS FOR ANY SUGGESTIONS--P.S. I HAVE A PINHOLE LEAK ALREADY IN MY FRONT TANK AND I'M GOING TO GET A MECHANIC I KNOW GOOD TO DO SOME OF THE TROUBLESHOTING WHEN HE TAKES IT OFF TO TAKE IT AND GET IT BRAZED OR SOLDERED AT THE RADIATOR SHOP.
I PUT IN A NEW TANK IN FRONT SIDE AND THE MECHANIC SAID THE FUEL PUMP ON THE BACK TANK WAS PROBABLY BAD AND SAID JUST LEAVE IT WOULD BE FINE--JUST LET ANYONE THAT BORROWED IT TO USE FRONT ONE ONLY
×