Question about 1990 Ford F150
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.
Posted on Apr 27, 2017
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Posted on Jan 02, 2017
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.
Posted on Jun 23, 2009
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.
Posted on Jan 30, 2010
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
Posted on Jan 31, 2010
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,
Posted on Nov 19, 2010
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.
Posted on Feb 28, 2011
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