Here's the deal. I currently have a 0-30 electric Autometer fuel pressure guage. It's tapped into the schrader valve on the inj. pump. Pressure on the guage reads innacurately ( tested with a mechanical ). I have a new sending unit on the way from autometer. I'm going to be putting in some sort of snubber, as I don't have one currently. My real question is when I unhook my fuel pressure gauge line from the schrader valve then re-connect it, the gauge works perfectly for about 2 to 3 starts. Is this symptomatic of a failing sending unit or is there something that can be done with the line itself to correct this?? Any help with this would be greatly appreciated.

-Scott

 

The air that enters the line when the sender is removed provides a cushion similar to what a snubber will until the air is replaced with fuel.
Longer hose between the engine and sender will hold more air and if it heads uphill may stay in the line for a long time. I've also seen folks put an inline fuel filter in the line to the gauge to hold even more air.