Earlier I had posted a message about my 72 1800E having a problem with running progressively lean and being imposible to start when hot. It would also die when temp was just above normal. I didn't think that it was the engine temp sensor because it had the correct resistance and I had just replaced it last summer when it gave up the ghost. But yesterday I decided to monitor the resistance from cold all the way to hot and found that it had a dead spot right at 180 degrees where resistance went to infinity making the computer think that the engine was at sub zero temps. This is funny because the old one had a dead spot too but at 110 degrees which caused a completely different result. So I replaced it and everything is working great for now and it only cost me $26.
This part seems to go out quite often so I recomend having a spare on hand and when checking the resistance be sure to check it at the temp where failure is happening.
Thad
Seattle, WA