The TPS should read 157mV when the RH throttle is closed fully, well below the idle setting. I think you would see about 400-500mV at idle. To get the butterfly fully closed, the RH end of the interconnecting rod ball joint needs to be popped off, and the idle stop screw needs to be backed out until it doesn't hold the throttle open.
If the voltage reading doesn't change smoothly from below idle to WOT, then it's time to get a new TPS.
Don't ignore the tiniest cracks in the rubber tubes between the throttle bodies and inlet stubs. Replacing these should be a 10 year routine job.