Fuel Pressure Gauge

[36coupe]

Hey All,

I'm running a SBC 350 with tri-power, I have a mechanical fuel pump to a fuel pressure regulator (set to 4psi) to a liquid filled fuel pressure gauge, then connected to a fuel log to tri-power.
When the car is cold the gauge reads at 4psi as the engine reaches operating temp. the gauge shows a lower reading 3-2 1/2-1 1/2 then to 0.
The pump consistently tests fine, I've changed the regulator and gauge. But the same problem, and the car runs great.
Any thought's?
Thanks, Bob

 

[TheLoneRanger]

Bob, try changing the orientation of the gauge. Try to get it with the face situated as upright as possible. My thoughts are that the heat is affecting the needle movement, along with gravity, and this is pulling the needle toward zero.

 

[36coupe]

Thanks I'll give it a try