Fuel pressure

[Broken down]

Hello

My Auto meter fuel pressure gauge, it go up and down from 40 to 20 psi very fast! when driving at steady speeds.Car is surging as well.So I looked at the gauge on the fuel rail it's not stable as well.But at Idel it's not to bad. Then when getting in to it some The gauge will go up , little bit more stable.
I changed the fuel filter.Didnt help
The pump is a Red Armstrong..Not very many miles on it. Under 4000.
But the car did sit for little over a yr.

Thanks for any help...Rob

 

[Chuck Leeper]

FP??

It could be the regulator.Pull the vac line and see if it's wet inside. If so, then the diaphram is leaking and that's the cause for the fluctuations.. If not that, does the fp rise about 4-6psi when you pull the vac line?? If no change, then the reg may be sticking, due to cruddy gas being left in it for a yr, same thing w/ the in- pump relief .
I'd check the easy stuff first, then drop the tank.. it may be the tank is full of rust and crud and the sock is collapsed.