85 camaro 2.8 liter

my 85 camaro has a really high idle and running very rich which is causing the spark plugs to foul my guess is its overloading but i dont know why also the electric fan isnt coming on and the temperature guage doesnt work they could be two totally different problems but mabye its a sensor or something thats making everything happen and if anybody knows were the temp guage sensor is on the engine id like to know so i can get that working id feel alot safer with a temp guage so if anybody knows or thinks they know what is wrong i would really like the help im stumped thanks.

High idle on a EFI usually points to a vacuum leak somewhere.

As for the fan/gauge, GM normally used 2 different sending units, one for each.

EDIT_ after posting that I wonder if you have a faulty coolant temp sensor, which may tie all the problems together. Any trouble codes?