Whats a good fuel pressure gauge?

[Monk]

I've a Holley fuel pressure gauge (non liquid filled) and a liquid filled one.

The Holley reads a pound higher than the other one.

The Holley goes up to 15#, the other one 8#.
Holley gauge is several years old, liquid filled one is new.

So what's a good brand of fuel pressure gauge and is there any way to check 'em?

[TheSilverBuick]

Something BBR clued me into on the EFI side, is that the liquid filled ones will read lower once they get some heat in them. He told me that, and I freaked out the first time I noticed it after driving the car a while and popping the hood seeing the pressure down ~10psi, before remembering what he said. Supposibly if I drain the fluid out that problem goes away? I trust the liquid filled one when the engine is cold.

[Monk]

Something BBR clued me into on the EFI side, is that the liquid filled ones will read lower once they get some heat in them. He told me that, and I freaked out the first time I noticed it after driving the car a while and popping the hood seeing the pressure down ~10psi, before remembering what he said. Supposibly if I drain the fluid out that problem goes away? I trust the liquid filled one when the engine is cold.

Well.........the engine was hot.....makes sense.

I'll check it again first thing in the morning (liquid filled one) and see.

[Scott Liggett]

Something BBR clued me into on the EFI side, is that the liquid filled ones will read lower once they get some heat in them. He told me that, and I freaked out the first time I noticed it after driving the car a while and popping the hood seeing the pressure down ~10psi, before remembering what he said. Supposibly if I drain the fluid out that problem goes away? I trust the liquid filled one when the engine is cold.

Mine didn't. Still drops when it gets home.

[Monk]

Well here's a note from Summit on the liquid filled ones:

When reading fuel pressure, keep in mind that a fluid filled pressure gauge will change it’s reading as the temperature of the gauge case changes (Under hood temperature). Because it’s sealed to contain the liquid inside, a liquid filled gauge no longer compares line pressure to actual atmospheric pressure, reporting the difference. Instead, it compares line pressure to the pressure inside the gauge case. As the liquid in the case heats or cools, it expands and contracts, causing case pressure to change as much as 1 psi for every 30 degrees temperature change of the gauge

[CDMBill]

I quit using mechanical gauges as the teller of truth when I went to EFI. I'm using an electric Auto Meter Sport comp in the guage cluster plus a little Aeromotive mechanical at the regulator under hood.. For the nitrous another sport comp electric. I like the electrics as you can data log the 1-5v output of the pressure sensor.

The little mechanical is always a psi or two off he electric, but who's to say which is right? ultimately the tune and how the car runs guides what setting for pressure. The gauge lets you track anomally's in fuel supply.