Fuel Pressure gauge

Greetings, So I fired up my 1940 D2 after a way too long restoration. During the startup everything was good, a few bugs with the pony but everything was a go. Oil pressure, temp, etc. But while I was bleeding the injectors I was watching the fuel gauge and I had nothing indicated. I had pressure at all other points of bleed as I was working so I figured it would come up. Well I finished the bleed and nothing, I cracked the throttle a bit and threw the compression release for the heck of it and it was running in an instant. After warm up it throttled up and drove like a new machine. So my gauge I bought via e-bay quite some time ago. I'm assuming its bad. Would anyone know what I'm supposed to be seeing on my gauge as far as lbs of pressure? I have a couple pretty cool old fuel pressure gauges in the shop I may use until I find a suitable Cat gauge but I'm curious at what optimum pressure should be. Thanks as always for any input, ideas, comments, etc, etc... :confused2:

15 psi was the expected high end fuel gauge pressure.

Hi Team,
here are two scans, one of tests done at our Dealership back in the 1960's
The normal full fuel pressure was specified at around 30 psi.
15 psi is when the gauge reaches the centre of the green on the 3H3344 gauge or, Normal range on the early gauges.
The pressure will rise in the system but the gauge will act as outlined with 15 psi being the lower end of usage below which power loss will start to be noticed on the engines in question.
We found on later high horse power engines that power loss started to show at around 24 psi and below, in some applications it was more like 27-28 psi.
Cheers,
Eddie B.

Thanks guys, That's exactly what I need to know! :tea: