Car starts but dies when I take my foot off the gas

[DaraSue]

Starting a new thread because the old one had drifted off the original topic.

The story so far: Car wouldn't start the day after getting home from a 400 mile road trip segment (out of 700 total). Found a melted plug at the resistor end of the Y/W wire between the ignition resistor and the coil. Re-terminated the wire, car still wouldn't start. It would catch if I kept my foot on the gas but die as soon as I let off. I'd had a starting problem while on vacation but it started and ran a couple hours later, with no significant issues on the trip home (San Diego to SLC).

This morning, I was able to keep it running with my foot on the gas, enough to back it out and then pull back into the garage (it died once and I coasted back in part of the way). Just now I tried it again, with the air filter off to check the mixture flap, as advised by Mike at MW. This time, it actually stayed running at idle, although low and rough. I didn't leave it running long. It took a little bit of pressure to open the flap on the mixture control afterward.

Has anybody seen this issue before? The filter was a little dusty but not horrifically bad. The fat plastic hose from the side air intake wasn't clamped on, though. I didn't see anything obviously clogging the filter.

Pix of the wiring by the mixture flap and the filter:

Picture 328.jpgPicture 329.jpgPicture 330.jpgPicture 331.jpg