Question
All zones work good except one.on that one zone sometimes all the
heads spray really good.but most of the time not.dosent matter if you
do it manually or by the timer.I replaced the valve but getting same
results  

Answer
Hey Larry, if you already replaced the valve, then that is not the problem. It could be that there are too many heads on that valve, or it could be there is a leak somewhere on that valve. Are you seeing alot of water in one area when you turn that valve on? To check to see if there are too many heads on one valve, you could simply dig up one head, and unscrew the head off the nipple, and put a cap on the nipple. Then turn the valve back on, and see if the heads work better with the one head capped off. If it does, you might want to think about changing your nozzles on the existing heads to lower percipitation nozzles. Simply put, these nozzles would use less gallons per minute, but would throw the same distance you would need. A valve can only put out so many gallons per minute (# of heads on a valve) if you go over that amount, then the system will not work properly. Good luck and have a great day.