Probably because it is clean, leave it on the filter setting for a while and you will find that the pressure will increase as the filter gets dirtier, when it get high (usually in the red ) you will have to backwash.
Did you replace the fuel filter? It can also be a bad fuel pressure regulator.
No this has waterin it when it is in backwash mode and rinse mode otherwise it is empty.
The pressure is lower as the engine is at slower rpms. The oil filter could be clogged or the oil pump might be going bad.
Have the fuel pressure checked. If the pump is noisy it is failing. do not forget to replace the fuel filter. A clogged fuel filter will appear as low fuel pressure, and overwork the pump.
Is this pressure of water going in a filter or pressure of water coming out a filter? Do you mean increase the flow of water? An increase in the filter pressure alone without going to a larger size impeller or newer pump will only indicate that the filter is getting dirty. If you need more flow consider changing the impeller or even upgrading the pump BUT you have to know what the outcome of that change will be. You have to know what the hydraulics and pump curve is in order to keep from overpumping the water. Too much flow can be detremental to the plumbing, the pump, the heater. Going to a large size pump most likely now increase your flow if the pipes can not handle that extra flow of water. Sometimes whrn a pump is not sized properly - going to a smaller size pump or impeller - whichever the case may be - will increase the flow of water or GPM. There is a is a trick or formula for sizing pool pumps, filters and heaters to a particular pool.
You will need to replace the fuel pump and filter, The fuel pump is what makes the pressure.
You check fuel pressure on each side of the filter.
The fuel pump may be running but not pumping any fuel. Have a fuel pressure test run.
the fuel pump is in the gas tank and the filter should be on the line coming out of the tank that goes to the engine.
It better have. Otherwise you need a new pump. And that is possible!
Pressure, supply,
by restricting the flow and installing a pressure switch.