Jon D,

The supply must be connected to the suction side of the fuel pump. If yours is stamped IN...it leaves no doubt.

It isn't crystal clear which end is up on these pumps...are you sure you have the wrong one.

The pump lever points UP, and if yours has a glass bowl, it probably makes it on top. To my knowledge, this is the correct orientation for the pump.

Internal valves make it direction sensitive.

Stuart