Difficulty starting, dies

[FordPrefect]

Ok. Moving this from the electrical subforum, cause I think the alternator is ok.

Drove my car ('76) on a long distance trip, and the alternator pooped out around 20 miles from my destination. Replaced it (new 95A alt, bypassing old regulator), and the battery, since that was also on its last legs.

Car takes ages to start, runs really well, then dies. Sounds good, no odd noises, just slows down and quits.

I've:

Gapped the points (gap was non-existent)
checked the plugs (wet from lousy spark, after points adjusted they look nice)
checked the idle speed and mixture (far as I can when the car doesn't run long)
made sure the fuel pump is pumping (line that goes into the carb filled up a jar ok, swapped in an old relay with no change, double checked wires at the pump)
idle solenoid functions
sprayed carb cleaner all over the intake manifold looking for vacuum leaks
timing is as close as i can get without the car running long enough to dial it in

Things I'll probably do next:

change fuel filter
change oil
swap out fuel pump

I'm pretty much stuck at this point. Any ideas?

[RRoller123]

sounds like fuel pressure declining.

[FordPrefect]

That's my guess. How could I tell if it's the pump or the power delivered to the pump, seeing as how they are tied together?

[garion]

Could it be the idle-cutoff on the carb (if you have one?)

[FordPrefect]

Success! Ran down a wiring diagram and tested the fuel pump circuit, got a healthy reading everywhere. Jumpered the relay to run the pump alone and the carb flooded immediately.

Popped the top off the carb and the float needle guide was unscrewed. tightened it, set the float level, and now she's purring.

Thanks everyone!