Temperature Sensor Failure?

[kustom]

I haven't tested the resistance numbers yet, but is it possible for a temperature sensor to slowly fail over time, or does it just die? If I unplug the sensor, it will stall. My car starts and runs fine, but as the engine warms up, the idle increases from 1000 to 1500 RPM. I was thinking temp sensor because I think it's also running on the rich side, and is getting bad fuel economy (about 250 km or 1556 miles per tank). Other than that it runs great... good power, starts well, runs smooth. Any input would be appreciated!

[So Cal Mark]

the sensor in the water tee is for the computer and is the main input to control fuel mixture. It can be out of spec in a narrow temp range or fail completely. Usually the car won't run if the sensor fails or if the connection is bad. To test it, you need to check resistance throughout the temp range

[RRoller123]

This is from IAP's web site for the temp sensor in the coolant T:

Temperature Resistance
(deg F) (ohms)
14 7,000-12,000
68 2,000-3,000
122 700-1,000
176 200-400
185+ Less than 200

Pete