Gas tank switch over valve stumped
 

Well I thought I put some foreign material in the lft tank not sure, soon after the truck would run out of gas on the lft tank and NOT switch to the rt tank with the electric switch. right tank would run fine and took me home from vacation . Pulled the left tank to check for foreign material it was completely clean and no rust. blew through all the lines and free. put tank back. still runs out of gas on the left tank and then will not switch over to the rt tank, take the supply line off at the inline clear filter b4 the carb fuel pump and then the switch over will go to the rt (good side). changed out the switch over valve still have the same problem. blew out all the lines and all seem free I AM STUMPED ON WHAT TO DO NEXT. tried to test all this without the gas caps on vent is free and this is the 6 port switch over valve with a supply return to the carb pump on my 80 dually 1ton pu. 454. and a supply return to each side saddle stock tanks. any suggestions I am lost for what to do. next. thanks Ed ke6bnl left side is energized with 12volt pwer is working to the valve.

Maybe The Valve It Self Is Messed Up ?????? Mine Locked Up Basically In The Middle Of Switching Tanks $55.00 At Dealer And I Drove Again

Just put a new one in yesterday thanks that what I thought was happening. I switch the tanks and put my air hose on the supply to the fuel pump and can hear air rushing out of each tank. thanks Ed

im kinda confused by this myself but you mentioned something about removed the inline connection around or at the inline filter and it will switch, i would try changing the inline filter maybe it is building pressure at that point and not allowing it to switch ??????????i dont know this to be fact but sounds logical to me what do you think let me know if i can be of anymore help for suggestions 86 gmg

we are thinking along the same line, I took the filter out and cleaned and reinstalled. The only strange thing is that this is occuring with the left tank only if I do not use the left tank the rt will perform as normal. once you switch to the left it will run for a short while, then will not switch to the rt tank, the running out of gas type symptom occurrs I was able to go about 35 mph, any more gas pedal would run out of gas and die.. This is one of those problem that you have to probably play with yourself to find the glitch. It is a simple system and that is part of what makes it so frustrating for me. I quess it could be a collapsing hose about the tank but I hate to pull that again they did seem fine and seems hard to occur with the thick fuel hose with 1/4 and 3/ line. Thanks for your input I will try it again tomarrow when my wife is home if she has to come and pick me up dead on the road that is the truck dead on the road. thanks Ed

sorry to her that mt wife hates it when she has to pick me up (not near as much as i hate it though :haha:

do you think that the sending unit (i think thats the right name unit that screws in to the top of the tank might have a pine hole in it somewhere that is sucking air and fuel? i bent a fuel pump hose barb once i didnt think anything about it but the damn truck wouldn't start changed pump it worked that reminded me of staightening the pump in the beginning, where i bent it cracked and allowed air to pass through
hopefully this will be the problem b/c i think im out of ideas check the fuel line between ele. switch and left tank as well for a small rub or something best luck!!!! 86 gmg