Should all injectors be firing at each click? I got 20 clicks, but only the third injector (counting from the back) felt like it was clicking.

Also, I am having fuel pressure problems. It is either a weak fuel pump, or I did not have enough fuel in the tank. It seemed like the fuel pump was sucking air with the fuel out of the tank. I only put a gallon or so in my tank that was bone dry, so either I didn't have enough in the tank to really submerge the pick up tube, or my pick up tube has a hole in it(like when you have a hole in your straw). I would have just put more fuel in the tank, but I have a leak, so I have to fix that first. Is there anyway to test the fuel pump to see if it is strong enough?

Thanks,
Justin