Guys,
Up until now my '81 temp gauge is perfect and cooling always keeps it really close to 190. Last night I was driving 100km/h or so and I saw the temperature gauge go down to about 150 and then bounce down to almost 120. I seemed like it was moving almost randomly between 120 and 170. On the drive home it was fine again with very little movement.

Is the car trying to tell me I need a new temperature gauge or sensor? During this time one of the fuses may have jogged lose as well (my right rear tail light dash lights were out which I didn't notice until it was dark on the drive home). Could this be related to the temperature gauge misreading?

Richard,

Start simple.

Mine's a carb car but I think the FI one's are the same. You have the two sensors in the head between the spark plugs? Just pull off the connectors, one by one, clean and snug the contacts and spades. While you're there look over the wires too. It gets hot in there. I actually had to splice in a short piece of wire as the old one was frayed and weak.

Bet that takes care of your issue.