No fuel pressure Options

[jfab]

I got my 1970 914 1.7l with all new fuel lines, car ran a little rough and almost stalled out when I let off the gas when revving it in neutral. First thing I did was replace the strainer. Fuel filter, and cleaned the tank and put new gas in it. Yesterday i started it up and it ran just fine! Turned it over today and i have no fuel pressure at the fuel rail. I turn the key and hear the pump working, but it won't start. Changed fuel pressure regulator, no dice. Also the clear lines near the battery that run into the engine bay has an air bubble in it and I noticed there is no fuel moving through that either. I'm completely stumped if anyone has an idea. I'd swap the filter but I put in a brand new one yesterday and it worked perfect then.

Could my fuel pump be bad even though I hear it working? The fuel pressure was staying at just under 40psi yesterday and randomly dropping to 20psi, even lower when I let off the gas pedal.

Any insight is appreciated