I am by no means an expert or full time irrigator, however, i can usually fix and install most systems. This one has me stumped on my parents system, thank god it's there! There were a few zones not coming on so I rebuilt the valves. The number 4 zone which only feeds 3 heads still didn't work. I decided just to put a new valve in thinking that HAS to be the problem. There IS water to the valve as I can hear it when I turn the supply on 3 feet from it. I can open the bleed and water comes out as well as the solenoid. However, turning the valve on manually or with the controller yields a dead zone. With the valve manually open the water meter isn't running, so I don't believe there is a leak nor do any pools accumulate anywhere. The length from the valve to the first head is only about 20 feet. The only thing I can think of to cause this is that maybe the adapters are too tight blocking the exit on the valve. Any advice?