ok i have an 86 iroc with the original carbed 305 block. i know the one sensor on the driver side of the block is for the gauge, but what exactly is the one on my thermostat housing, and there is one on the passenger side head, and one on the passenger side of the block just above the oil pan. what are they and what do they do? thanks for the help everyone!

 

OK, i will say what i believe they are,

1: coolant temp

2:fan switch temp

3:nock sensor

4:computer temp for choke

You have the factory computer controlled carb application, so i think these are what they are, hope this shines some light, a chilton would confirm.