Here's an easy one

[handleyb]

1970 T with Zeniths. Do you test the fuel pressure with the car running or simply with the fuel pump activated ? Thanks

[Joe Bob]

Inline gauge or regulator....

[D911SC]

I can check mine on the inline regulator/gauge with just the fuel pump activated.

[handleyb]

I just put in a regulator. Adjusted it to 3.5 with pump activated using an inline gauge. I'm not sure if the pressure will change with the car running.

[HawgRyder]

If the pump gives out the correct volume...then the pressure should remain the same.
If the pump is undersized or on the way out...then the pressure will drop.
In any case...reving the engine and observing the resulting pressure will tell you the condition of the pump...or hoses (old hoses swell on the inside restricting flow).
Bob