my truck came with two tanks and I know that the selector valve is not functioning. is it possible that a non-functioning selector valve could allow gas to flow into the other tank while the pump is working? I ask this cause my truck is getting about 1/2 mile to the gallon and I know that there is no way a stock 350 in a stock truck will burn this much gas and if the carb was feeding it this much it would foul the plugs. Ive searched and cant find any leaks but I ran out of gas after dumping in 2 gallons and driving about a mile up the road. my second question involves bypassing the selector valve. I know it will work if I run a single tank but I like having the capacity of two. would everything still work right if I ran the lines from both tanks into a Y fitting and then to the pump? It would be similar to having one big tank but Im wondering if the pump would still pump the gas correctly and would it still work if one tank ran out while the other still had fuel? thanks.