Update...air fuel mix screws on the Carter AFB 3720s 4 bbl carb were only opened a little more than 1.5 turns but it was definitely running rich. I closed both screws and then re-opened them to just one turn. The car started and ran right after. However, the next morning it would not idle. I opened each screw about 1/8 more turn and increased the idle speed.
What I find interesting is the timing light showed the timing mark well above the timing tang. I remember setting the timing mark about 5 months back to be about 10-12 degrees and it was on the tang. How did it change? I did have some work done on it for me so maybe the timing was changed then - I will ask as I do not believe adjusting air fuel mix will change timing. I used the timing light to get the timing back to 10-12. Does anyone know how a timing light can change timing? I always thought you had to move the distributor.
The air fuel mix screws being adjusted and changing the timing did the trick. I went back to the same emissions shop to see if they would do the test again. They did and there is a great improvement - see the picture below as compared to the first picture in this post. Now, there is only high HC and high CO at idle which I believe is a timing issue, but not sure.
