Coolant Sensor, Again!

[LSGarage]

Back about June or so I problems starting my truck ('86 S-10, 2.8 TBI). Someone told me that it could be the coolant sensor giving bad info to the ECM. They gave me a list of ohm vs. temp readings to troubleshoot with. I changed the coolant sensor and the truck began starting better. But as soon as it went below freezing this winter the truck wouldn't start again. After changing the fuel filter, it checked for spark but couldn't detect any. I checked the coolant sensor at 50 degrees with a another new one and found it about 2000 points off. I installed the new one and the truck started right up. The only difference was that I installed the new one without pipe thread sealing tape this time. Could that have been the cause of the failure of the sensor I installed in June? The original sensor lasted 20+ years and over 180K miles, the second lasted 6 months and 3000 miles. Did I just get a bad sensor?