Listened to your YouTube videos. I've been through my '85 LTD with a fine tooth comb, and I would find an interrelation between the injectors and TPS such as what you have unlikely. Stranger things have happened. Looking at the wiring schematic there is no connection that the TPS and injectors share. Wiggling/moving the TPS wiring may be affecting the injector wiring in the wiring harness, something to check.
The TPS can be an issue. You can use a multimeter as has been mentioned, but a scope is much better. I have a large scope that I am learning to use, but purchased a DSO 138 Oscilloscope (assembled) to check these types of issues, you can get one assembled in an acrylic case. Tried it out today on 4 TPS units I have and found some cannot be used. The QA on these units is not the best. Heat also affects the TPS in that it makes it degrade faster. If the TPS gets too bad, you can have the engine have hard misfires that feel like the engine will stop - BTDT.
I changed the TPS on my '85. I used a Dremel tool to cut a slot in the bolt, and then used a screwdriver to extract the bolts, works well. Once you have the TPS loose you can also try a calibration as well. Attached a picture (poor quality) but you will get the gist of it.
You can use aftermarket TPS units such as this one on eBay: https://www.ebay.ca/itm/TPS-Throttle...BWvT6K&vxp=mtr
You have to a slight modification to make these work. You drill a small hole in the rheostat arm near the end and insert a small screw. For added strength, use JB weld and build up the area around the screw. Keep the JB weld narrow around the screw. There are three pics showing what I did to the aftermarket TPS. The last pic shows the OEM TPS.
The aftermarket TPS mod worked well on an '85 LTD that I brought out from Ontario last June, and put over 8000 Kms on it before I sold the bike. The JB weld gives excellent structural support to the small screw.
If you have the external alt mod, there is more you have to do to make and aftermarket TPS fit, but that is for another day.
Good luck. Cheers