Fuel not pumping when cranking

[#Brock]

Fuel primes on reds but stops when trying to start. Have replaced oem reg with rising rate reg in the past running fine. Took return fuel line off to reg n primes on red but doesn' flow when trying to start the engine.

 

[accentstencil]

Once the fuel pump primes I'm pretty sure that the pump won't start again until the engine starts.