Well, I managed to get the 242 to pass emissions. The standards are: Hydrocarbons (HC) less than 200, Carbon Monoxide (CO) less than 1.00. The first trip I failed, with HC at 154 and CO at 5.39. Somehow I had to bring down the CO! So, I decided that it was time to replace the fuel injection on the car with a better unit that I had found at the junkyard on what appeared to be a very well maintained 78 245. I spent about 8 hours doing that and removing the air conditioning system, with far too much of the time spent fiddling with the non-AC power-steering bracket.
The reason why I replaced the fuel injection lines/distributor/control pressure regulator? I suspected that the distributor had a slow fuel leak, and indeed, when I pulled it all out, it appeared that it did. Well, I gambled and won, because the new unit was much better than the old. The idle was smoother, the car revved smoother, and overall the car had more power. Obviously the high CO of the first test indicates that I was probably running rich, and this appeared to have fixed it.
The second test gave me these results: Hydrocarbons at 499, CO at 0.27. Well, now the CO was well within spec, but the hydrocarbons were off. So I left the test center, pulled over, got out my 3mm allen wrench, and turned the mixture (CO) adjustment screw about 1/4 turn to the left. I tried 1/2 turn, but the idle started getting bad, so I just kept it at 1/4. Then I drove around the corner and back to the test center for round three!
The third test was the charm – I passed with Hydrocarbons at 193 and CO at 0.09, less than the respective limits of 220 and 1.00. I drove to the DMV and got my new registration tags, and the car is ready for another couple years. It also runs much better and probably will give me better fuel economy as well.