Hesitation/Stall question

I am thinking that if my cam is suggesting that a 2000 stall works best this could be the issue, not high enough RPMS when in gear and idling to pump up enough fuel maybe?
Just not sure if I am on the right path.
Mechanical Pump operation is dependent on exactly three things; rpm, head, and ability to pull. This assumes the return spring does it's job and keeps the pump arm on the eccentric.
>If yur tank vent stops working, it gets harder and harder for the pump to pull fuel.
> the fuel volume test in the FSM, stipulates a 500 rpm idle speed.