Fuel Pressure Gauge Bouncing

The fuel pressure is bouncing all over the place, in spite of there being a regulator.

[derkanerka]

Do you have a mechanical or a electrical pump?, mechanical pump on a return style regulator will fluctuate like that.

[texascarpenter]

You need to fill the gauge up with silicon oil

[chiefexecutive]

What gauge and regulator is this and are you using an electric pump ?

[NoPeoblemX]

It has air trapped in the line somewhere

[vicpetrishak]

Install a quality glycerin filled pressure gauge or restrict the fuel flow to the gauge .

[dariusbrown]

It’s hooked up wrong, where you control the fuel pressure you have a fuel line coming out of it lol take the fuel line out the top and install the fitting.