Galley Water Pump
a couple of things come to mind. You could have air in the system, or your accumulator tank is going out. I typically get air in the system if I run it completely dry (e.g. forget to refill the tanks in time). If that''s the case, the easiest thing to do is to run the system continuously for a while to help the bubbles get out (works for me). However, if you have some real loops in your water hoses, air might just get stuck there, and you''ll have to resort to nastier methods.
The accumulator tank actually provides/maintains pressure in the system. Basically, the water pump turns on and builds a certain amount of pressure, and then shuts off. If you now turn the fosset on, the accumulator tank provides the initial pressurized water. If it''s busted, your initial pressure will be low, and the pump may cycle excessively on/off.
Hm, one other possibility is that you just set the pressure to low on the ShurFlow pump. If I remember correctly, most of them have an adjustor close to the inlet/outlet. However, this will only make a difference if the accumulator tank is working.