1993audi90

1995 audi b4 aft engine. I have a pesky 2121 (dtc 00516)(closed throttle pos. switch-F60) that keeps coming up.
On the voltage supply from the firewall, I get 5.5 volts on terminal 1-2, but only 3.5 v on terminal 1-3. I'm supposed to have 4.5-5.5v on both tests.
Also, on checking the TPS itself, and this is really odd because I get the same reading on three TPS' I have-- on the wide open throttle ohm test, it goes up to 2000 ohms as I open the throttle, BUT then all three TPS go blank-nothing at about 2/3 wide open throttle. The reading is supposed to be 3600 ohm max on terminals 2 and 3. It seems odd that I get no ohm reading at full WOT. All three TPS pass the first two ohm tests, but all are junkyard pickups so are all three bad?
. I did adjust the accell cable and this is good.
Anyone encounter TPS issues before?

CRAZY_RUSSIAN

4th tps is a charm? if you get your hands one the 4th one, run your tester first, before plunging in to your harness. so if it tests out OK at first and then you fail your test after it was pluged in to your car, you know its your car and not the TPS