79 f-150 duel gas tank trouble
10-16-2011, 12:46 AM
#1
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79 f-150 duel gas tank trouble
I just got a 1979 F-150 (ranger xlt) and it has duel gas tanks the front one works when I flip the switch to the rear my gas gauge goes to E but it continues to run. I found the tank selector valve and pulled the gas line to the rear tank (while running from the rear tank) and it still ran and there was not suction. Is the most likely cause my selector valve is not working or what else could it be and how do I tell?
10-16-2011, 09:07 AM
#2
Senior Member
Do you know how much fuel is in the rear tank?
Not sure how the older models work but if like the '86 then it works like this.
When front is selected a solenoid is activated to switch from rear to front. When rear tank is selected (or no power) then the valve is switched back to the rear tank by spring action.
You should be able to hear or feel the solenoid click when you have someone change the switch position.
If not pull the connector from the valve and connect a test light or voltmeter and test the switch.
If that is working then I would remove all fuel lines and operate the switch while blowing air through the inlet and see if the valve is switching properly.
Not sure how the older models work but if like the '86 then it works like this.
When front is selected a solenoid is activated to switch from rear to front. When rear tank is selected (or no power) then the valve is switched back to the rear tank by spring action.
You should be able to hear or feel the solenoid click when you have someone change the switch position.
If not pull the connector from the valve and connect a test light or voltmeter and test the switch.
If that is working then I would remove all fuel lines and operate the switch while blowing air through the inlet and see if the valve is switching properly.
