I have a 4 zone set up. This year Zone 2 would not turn out. Turns out that it was a bad wire. Luckily there was a spare wire run to the box so swapping it out was simple. The problem though was once I got zone 2 working, zone 3 went on the fritz. It is having the same symptoms that zone 2 had. The zone will not turn on. I have Toro 264 series valves. If I open the bleed screw, the zone comes on. Then when I close the screw, the zone stays on. But the problem is that it won't shut off. I swapped the selonoid with one of the other working zones and that did not fix it. I also swapped wires and it didn't work. Today, I took the valve apart and cleaned it really well. I also bought a new diaphram and installed it, still the valve will not turn on unless I open the bleed screw. And when I do that, it will not turn off once I close it. Is there something else I am missing here?? Any one have any other suggestions. Between these 2 zones, I have been fighting this system every day after work this week!