I did a search on overheating, found someone having a similar problem to me. He was told to check the resistance on the coolant temperature sensor, and that that sensor would be on the left side of the engine. There are two wires running to two spots right next to each other right there, if I have the right spot- which one is the coolant sensor? Also it says check based on a "known" temperature- I have no idea what temperature it is in there, should I just try to find out what the fan kick on temperature is and go by that?

For background, the temperature gauge reads 240 before the primary (driver side the primary one?) fan kicks on. Of course, if it was really 240 I'd imagine there'd be tons of coolant spewing into (and out of) the overflow tank and the other fan shoulda kicked on as well.

I believe he said he changed his coolant temperature sending unit and it still misread the sensor- if indeed mine is just off, how was that fixed?

The car is a 91 Z28, 305 TPI.