My gas gauge sending unit in my 86 4Runner is bad, when the gauge reads 1/2 a tank im out of gas. I was told that the fuel sending unit and fuel pump are mounted together in the gas tank, is that correct ?. I was looking at the factory service manual and it looks like the fuel pump and the sending unit are two seperate units and mounted in seperate locations on top of the fuel tank, are they seperate from each other ?. does anybody know how much a new sending unit costs and a good place to buy it from ?. I have access to a used sending unit from a 91 truck, would it work in my 4Runner ?.