If I understand your post, your fuel pump is not activating?

If the relay is new from *after* the problem then it's *probably* not the issue. But you can ocassionaly get a bad replacment relay. It does happen, not often but it is a possibility. Be sure the new pump relay works and eliminate it as a potential problem. I think the FAQ decribes how to test it. You could also test your old one and see if it was ever a problem.

The RSR is the most likely culprit imho. They fail suddenly or intermittently cause a lot of trouble for people trying to diagnose the fault. Testing it is very easy. Just flip the fan RSR (you have two identical ones) and see if there is a change. Conclusively eliminate the obvious, then move into the less-obvious. The RSR has already been mentioned but let us know that you tried it.

If the pump does not activate at KP2 then I'd suspect an electrical fault. Since it happened on a turn, I'd further suspect that something shorted out or came loose. I never figured out why my own regina car died on a turn at sonic. It never happened again and I never diagnosed it. I chalk it up to haunted car syndrome, but I say that only in jest, as some people will get upset if you trash-talk an entire car. However, when a motor mount broke on my 145, a hard break caused the engine to lurch and a wire to my coil(not a spark plug wire) pulled loose killing the car. I was able to figure it out easily, but there is a lot more open space under the hood of a 1972 145. Double check every electrical connector. It could be something no readily visible.

You can also check wire continuity at the pump/sending until wiring plug in the rear. Incidently, your fuel gauge does work when you turn on the car, correct?