Re: stops running when hot
Just a thought, perhaps your are have a bad coolant temp sensor. This is not to be confused with the sending unit.
Clearly, your engine is running in the normal range as it is not boiling over and the gauge agrees with that. But, while the sending unit feeds the reading to the gauge, the sensor sends information to the computer for fuel trim curve and the like.
Perhaps it is worth checking the sensor against the specs. Haynes and Chilton's manuals generally will have the proper resistance values and procedure for your application. Otherwise, if you have access to a computer tool that can give you digital readout of the sensor value, which might prove more helpful.