Have you actually measured the resistance over the temp sensor, Michael? It should very precisely with temp…
The ECU applies voltage to one wire, and reads the result on the other - adjusting fueling accordingly. Ie, the sensor relates to the ECU, no other item is involved. Basically, with the plug disconnected the resistance is high (infinite) - indicating a very cold engine; rich fueling. Plugged in, the resistance depends on engine temp - at 88C the resistance is about 265 ohm; at 80C its 325 ohm.
In the video, you do not give engine temp; if the engine is cold it will/may run with the plug disconnected, but will seriously overfuel with the engine hot - and may then quit. As your symptoms, quitting when the sensor is connected, it raises questions of engine temp, and indeed the resistance in sensor, in the video test. Both should be checked - preferably with an infrared thermometer and a multimeter…
It’s indeed a puzzling situation. The main point is that the fueling changes when the sensor is plugged in, which actually is as it should be - but that the engine quits means mixture is outside engine running temp at the time.
You say the result is the same with other sensors used? You do not explain what testing was done when the wires were cut (and reconnected?)…?
With the sensor unplugged and ign ‘off’’; measure resistance over the two pins on the connector - it should be around 2 Kohm. This is really a test of the wiring from the plug to the ECU rather than a test of the ECU - but anomalies may be interesting. It may be an ECU fault, but as I seem to recall - you have tried swapping it with no change…?
xj6 86 Sov Europe (UK/NZ)