Pressure that’s too high indicates a malfunctioning pressure regulator. Low pressure indicates a clogged fuel filter or a broken fuel pump.
Cut the engine, relieve system pressure again and remove the negative battery cable.
Raise the Plymouth Voyager so you can access the underside of the vehicle and support the gas tank with a second jack. Remove the fuel lines to the fuel pump. Remove the straps and stays that hold the fuel tank. Lower the tank and remove the fuel filter.
Examine the filter for clogs and replace if necessary. If there are no clogs, the fuel delivery problem is probably caused by a breakdown in the fuel pump itself.