TPS signal issue, Will not idle, cuts out

94 XJ 4.0 AT 4WD

Started having some intermittent idle run issues.

Long story short it finally threw a code for a TPS, back-probed and found that the reference voltage good, but signal (back to ECM) never got below 2.8/2.9. Got a new TPS on, the similar results. pulled connector started digging into the wires probing etc. I am getting 4.3~vdc on the output wire to ecm (with sensor unhooked, Chased it all the way back to ECM. I cut the wire after checking ECM plug and i am getting 4.3 out on Pin 22. I had a spare ecm from a junker swapped that in still getting the 4.3 vdc. What am i missing?

Measuring the voltage on the signal wire from the ECU without a sensor installed is misleading. With the TPS plugged in, do you have a good ground and good +5-volts? Signal changing appropriately?

Have you verified the wires are good all the way back the ECM? It's not uncommon for the wires to chaff and short or break in the harness where it crosses from the back of the valve cover to the firewall, especially if you have bad motor mounts.

I do have good 5vdc
when hooked up i have .7vdc closed and 3.8vdc at WOT

3.8 seems a bit low. Does it change smoothly as you open the throttle? I'd suspect the throttle body and IAC need cleaned.

Isn't .7 too high? Just want to point out I went through 3 brand new tpss before I got one that worked right.

It dose move smooth. I am at a bit of a lose really. I am not sure why I can find a good set of data about what spec should be.