What is the purpose of the ground in this diagram?
A proper 3-terminal TPS is a potentiometer. It produces some proportional voltage between ground and the reference voltage at the top (5V or whatever)  A linear pot will output a voltage proportional to the distance between ground and the top.

But if you have only two terminals, then you only have a variable resistance (or you could call it a rheostat).  You could kludge a way to read your rheostat by first measuring the total resistance of the rheostat, and then selecting a "pull-down" resistor to "work against" the variable resistance in your rheostat TPS. You must know the TPS resistance in order to select an appropriate value for a pull-down resistor.