Good Morning.
I have a 1986 F150 6 cyl, dual tanks, no AC, manual fuel pump. Just recently, I have been having issues with the tanks. At first it seemed like the back tank was siphoning from the front tank. Now I have fuel coming out of my front tank filler neck. When I open the back tank gas cap, there is enough pressure to spray me with gasoline. I am not familiar with the fuel delivery system of my truck and was wondering if someone could point me in the right direction.

Thank you in advance!

Sheri

 

Isn't your 86 EFI and not carbureted?

Check these components in the thread to see if you have them. It is the most common issue.

https://www.ford-trucks.com/forums/1...tor-valve.html

 

Thank you responding LxMan1, my 1986 does have a carburetor. This is what I am seeing underneath in front of the front tank on the frame. Is that the valve assembly? I'm not seeing any other components from underneath the truck, except the line going to the fuel pump.