So it's been awhile since I last posted. Remember that aftermarket ECU? I found out it was bad and causing starting issues and the high idle condition. I happened to find an original replacement ECU from another 1976 2+2 and that solved my problem. I also found that the TPS was missing a screw and out of position on the throttle body. As it turns out, the missing screw had broken off inside the throttle body. I was able to source a used one and installed it. Everything now seemed to work except for the temperature gauge. This was baffling to me since I had replaced it with a new one when I replaced the thermostat and the housing. However, that one was a two piece unit. I tested the temp gauge and wiring by disconnecting the connection to the sensor, temporarily running a wire from the the connection to ground and turning the key to the on position. The gauge needle moved from resting position to max within a few seconds, eliminating the possibility of a defective gauge or wiring. This was reassuring, since I was not looking forward to having to troubleshoot a wiring issue, nor did I want to have to go and try to find another gauge. So, I purchased a new temperature sensor, this time a one piece unit. I had some free time to install it yesterday, and Voila! I once again have a working temperature gauge. Here's the one that didn't work: Here's the one that worked: And the proof: