Posted by Vaughn [108.162.215.115] on Wednesday, September 25, 2019 at 11:20:26 :
In Reply to: The Dodge Boys, Mechanical Fuel Pump posted by Dean Dysart [172.69.42.49] on Wednesday, September 25, 2019 at 09:39:56 :
The cam lobe that actuates the mechanical arm may be flat or the arm itself may not be angled enough to create sufficient vacuum or the diaphragm may have deteriorated from storage.
You could disconnect the fuel lines, unbolt the pump and hold the pump against the block with your hands to feel the action on the arm, place a finger on the port for the tank line and feel the suction it creates to test it as someone else cranks the engine.
It doesn't sound as though you have an issue with any other components since the electrical pump solves the issue.