So I found the connector for the temp sensor on the back of the head, for the gauge. It was not connected, plugged it in and the temp gauge works now. WOOHOO!!!

Also, I found the intake air temp sensor on the back side of the intake manifold, looks just like the coolant temp sensor with a two wire connector. I check resistance according to Jeep's specs, when the engine is cold, it is about 2k-2.5k ohms above spec, so the computer thinks it is colder than it actually is. Once it warms up, it is only about 200 ohms above maximum spec which may be a small enough difference to allow it to run better. Either way, I am gonna price out an intake air temp sensor tomorrow at work.