How are you using a DVOM? If you have one and consider yourself good at it: connect it to two terminals of the tps sensor. Rol the throttle to see a change in resistance. If there is none, move one of the leads to the other terminal and try again. It should change resistance as the throttle is rotated.Now move the meter to a high scale, SLOWLY roll the throttle to watch a linear change in resistance. If you observe a glitch such as a drop or goes to infinity you have found your problem. the glitch will be at the same throttle position as the stumble.
p.s. you can do this with the key off as to not cause any damage.