I think I may have a bad TPS. It attempts to shift into OD, then falls right back to 3rd over and over, around 40-45 MPH. Sometimes it will shift into OD and stay there once I reach 55-60 MPH.

I'm interested in trying the "potentiometer fix", but I can't find the location of the TPS even in the Service Manual.

One other question: Does cruise control still work with the potentiometer?

 

Right on top of the throttle shaft on the injector pump

 

It is a black plastic 2 inch square that has four holes in it for two bolts. A short pigtail plugs it into the wiring harness near the front valve cover. It sits right on top of the VE pump in front of the AFC diaphram. I small plastic blade sits on the throttle bolt and turns with the throttle. If you happen to take that out when you remove the TPS it would be wise to match mark it for reassembly.