A TPS is a potentiometer . You are using your meter to find a glitch . These glitches are going to usually exist at the position they usually operate at .
you don't need a Ouija board , divining rods or a peach tree limb , just a meter , a little knowledge and some confidence .
Watch a few videos , Google ''pots" and think about what you are seeing happen . This will be easier to test than you think . Just remember to move this throttle slowly while you test .
Also , get one of those diagnostic cables mentioned on this site that is used to set tps voltage . It will make things much easier !