I have a1996 Subaru Outback. We took a 300 mile trip on 1/2tank gas. 2weeks later we take same trip with cruise on and @150miles I was out of gas. So I refilled and came home to get another vehicle. On return trip I did not use cruise control and used barely 1/8th tank of fuel. Took car to shop turned it of and it refuses to restart unless I shake fuel line. The temp outside has beem 85F to 95F outside. What is going on? Shop has no idea.
You may have a fuel pump going bad, but either way, your sending unit is definitely no good. There is no way your Outback traveled 300 miles on half the capacity of the original fuel tank. This is why I never trust the fuel gauge in any of my vehicles, and you shouldn’t either. Every time I fill my fuel tank, I reset the trip odometer and learn how quickly my vehicle will go through fuel. This can give you some great advance warning on any issues your vehicle is having, including fuel gauge discrepancies.