On the head temp sensor, what's the typical resistance or output voltage range? I get 5 volts in and 0 out when the engine's hot. That what it's supposed to be?

Or better yet, is the a better manual that covers the more technical aspects of a 86 NA engine? Hayne's book I have doesn't really get into it.

 

yes, the factory service manual really goes into it.

and you measure the resistance of the CHTS, not the voltage (0 volts is because both sides are then grounded)

at 212 degrees, resistance should be about 200 ohms.

at 68 degrees, resistance should be about 2000 ohms.

 

Checked the ohms, it's an open circuit. I take it that's a bad sensor then?

 

Yes, a 0 to 1 ohm resistance would indicate a bad sensor.