What are the symptoms of a bad coolant temperature sensor?

I have a 94 isuzu trooper 3.2 liter V6 that has benn running funny, at first it was idling erratically so i took it to the shop and they reset the ais motor and it ran fine for a few hours then it suddenly started to lurch and stall out and then wouldn't crank back up as well as blow black smoke. The code that came up was the coolant temperature control sensor is this my problem or are these even symptoms of this?