You can get the same snubbing effect by sliver soldering in a section of cap tube inline with your gauge or sender, they come in various bore sizes and lengths.

Jim

 

I used a needle valve right out of the fitting. That way I can shut the fuel off if need be.

 

Those sending units aren't cheap. If ever, you run out of fuel and you go thru the bleed steps, before you even begin to start cranking her over, shut fuel off to sending unit/pressure guage. Happened to me, and trying to crank her over numerous times(still had too much air in system) I fried my sending unit. So, a shut off valve in line is all good. I piped it in valve 1st, snubber 2nd, 3rd sending unit. This, off course, would be for an electronic type guage

 

Thanks for everyones replies, it ended up being that the lift pump was shot. I installed a piston style lift pump set at 15 psi and all those symptoms went away.