Water Pressure when boondocking

[gojodo]

Our water pressure when boondocking is next to a dribble and that is about it. For maybe 5 to 10 seconds we get a good pressure if the pump is primed and ready but then it drops like a rock to a low pressure. I installed an in-line accumulator (I think that's what they call it) and it shows it is pressurized to 30 lbs which is what it calls for. I also have a new Surflow (top of the line) pump. Any suggestions would be appreciated. Thanks John Weber