1993 Nissan Altima will crank but won't start - sometimes - altitude issues?

I know this is a stretch, but I don't have a good explanation for this...

1993 Nissan Altima with only 85K miles on it. Lived most of it's life *at sea level* no issues.

not sure if it is related (coincidence perhaps) but due to radiator leak, experienced warped head gasket (repaired).

At about that same time, I moved from sea level to 5800 ft above. After repairs, I drove car (back to sea level) and had no problems. Upon return to 5800 ft, car sat for a few days. Tried to start it back up - it would crank but acted as if it wasn't getting any fuel.

I went away for several days (without car). Upon return, I tried to start it up, and it did. Had no problems over several months.

Yesterday, drove back down to sea level - had no issues starting car at sea level. Even after driving back home (to 5800 ft) stopped for gas, stopped to eat, had no problems starting. It sat over night. I tried to start the car this morning, and once again - cranked, no start.

Silly question, but would it have anything to do with pressure in rail? Temperatures vary from very cold at night to pretty warm during the day, add to that altitude issues. Seems like the only thing that would explain it's not working today (and I'm gonna guess that it will again start in a few days???)

Any ideas? Thanks