BMW VTPS fluctuating readings
 

Hello! Im fairly new to the megasquirt game, and I'm a little stuck on this Variable TPS signal. I have a 1993, entirely stock minus the wide band, intake, IAT and MS2PNP. I swapped over a BMW variable TPS and its fluctuating its values a lot. Ive been researching the subject for hours now, and still have a few questions. Ive opened up the harness on the passenger side, and have all the wires splayed out. My readings on the TPS only vary from about .1 to .2% at the moment.

A. I've heard that people twist the wires together, and this can mitigate the EMI. is this truly effective? I've tried to twist them together, but when I go further up into the harness I reach a point where the ground (light green/black) fade into the injector harness, and CAS plug. How could I possibly twist the two wires together. which wires am I supposed to twist together if those are wrong?

B. I don't fully understand how to shield a wire. I get how it works, but how is it supposed to be grounded? would I simply splice the shielded wire into the signal wire between the ECU and TPS itself? Ive heard of home made aluminum foil shields, but still unsure how thats physically grounded.

I hope I don't come off as completely ignorant, just unsure of what to do. For the record twisting all 3 of the TPS wires and physically moving them a little bit has helped a small amount that is noticeable on the TPS on the dash, which I guess is progress.