New issue: Fuel pump prime on key on 3sec then air bubbles in Tank, Hard start/no start ran OK once started Options

[rfinegan]

I drove my Djet 2.0 75 to the dr 10 -15 away. Came out 30 in later and car would not start.
Cranks
Fuel pump prime
Clear flood (crack peddle to the floor)
Just hitting occasion on a cylinder or so
Battery almost dead trying and I got it to start and get home(no tow bill)

Ran OK, but did not let it idle not wanting it to stall
at home I turn it off and would not start again

Symptom:
I can hear the fuel pump prime for 3 secs followed by a rush or air bubbles in the Tank

out of the blue, the fuel pump prime seems to prime normal and no bubbles and start and shuts off as normal

Sound like vapor lock? But I have never had this issue and only mild temp about 75-78

Gut makes me think fuel pressure regulator or fuel pump? NO check valve to hold pressure right? I need to get a gauge on it and make it strand me again....



May not be related:

To get it started before the battery went dead I swamped the advance curve on the 123 to the one that came with the distributor ( more max advance)

At home to hear the bubbles better I pulled the fuel cap to see the bubbles and here them better

In a Forest Gump voice: And just like that, it got better!

[rfinegan]

Wow that is a small hole for the expansion chamber tube to filler neck....but open and no obstructions all the way to the charcoal can or no leaks

Oh BTB: when it was acting up at home and the loudest bubbles, when I removed the filler cap no woosh noise for pressure of vacuum

Looking for leaks and kinks next...