on my 94 runner 3.0, .. when i start the engine from sitting overnight, the temp guage jumps over to the red side in just couple of seconds.. when I'm driving, the needle fluctuates from normal to hot. also getting very bad mileage, worse than usual. does the temperature switch need to be screwed in all the way? i screwed it in as far as i could get it which is probably half way cause i still see lots of thread showing. didn't want to over tighten the switch and risk breaking nearby sensors. the rest of the sensors are sitting flush against the base, its just the temperature switch that I'm concerned about. any suggestions?

 

Mine does this same thing. But it goes right to the middle like it's been running for awhile when it's actually cold. I would like to know where the sensor is to fix this on the 1988 3.0 v6.

 

Are u getting bad mileage as well? The sensors are located at the top rear of the engine, just behind the plenum. Removing the plenum is the best way to changing out the sensors. It's just a PITA to get to.