On the bottom side of the upper manifold right my the EGR valve there is a sensor. What sensor is that and are they know for going out?

 

Near the rear? If you are referring to what I think you are, that is the Intake Air Temperature sensor.

"Cheap" part but a PIA to reach. Leave the dead one in place, unplug the wire, extend the wires & relocate it to a cooler spot in front of the Throttle Body & use a better sensor.

http://www.austinthirdgen.org/index.php?pid=24

For those that say it that it makes no difference, a Quote from the write-up.....

"However, from my practical experiment using datalogging software, I can say without exaggeration that I've seen a 35-degree (F) CONSTANT difference in the intake air temperature measurements.

With the stock TPI IAT (heatsoaked CTS part), the computer saw 132 degrees in the intake on a 95 degree night. That measurement was performed on the highway, i.e. with lots of air flowing through the engine compartment. Stopped at idle, the temperature reading was even higher.

With the relocated TBI IAT sensor, the computer saw 97 degrees on the SAME night, with 95 degrees outside. Again, this measurement was performed on the highway but the reading did not increase much at lower speeds or at idle."

 

Thank you, If this sensor is bad could it cause a very rich condition?

 

If you have a MAF, the MAT sensor has no effect on mixture, it's only used for EGR operation.

If you have a MAP, it can have a small effect.

If you running very rich, I would check the coolant sensor first..

 

Where is the coolant sensor? Is that the one under the TB? also, I took the gauge out from the drive side head and installed a mechnical Temp gauge.

 

Its on the front of the eng, just below the thermostat. The connectors tend to fall apart after a while. You can check the resistance of the sensor and compare with a temp/resistance chart like this: