First of all , you have to many heads on one valve station.
I don't put more than maybe 5-6 heads on one valve.
Everything needs the same flow and pressure. I like to start by finding out
my flow in Gallons per minute, from the source. Try 5 gallons per minute to
start with. I like to use 3/4 in. Class 120 pipe to feed the system. Not
Sch. 80 pipe. The class pipe is bigger on the inside for more flow. Flow is
everything, then pressure.Hopefully you have at least 40 -60 PSI at the
source.Buy a cheap pressure gauge at the plumbing supply store and check
this first. Then get a five gallon bucket and see how much flow you have by
filling the bucket . Time how much water goes in the bucket in 1 minute,
from the source.
Should be 4-5 gal. per min.
Also try to turn down the flow from the valve at the stations that have too
much water.There should be a flow control on the valve. Go to a Irrigation
supply house and ask questions. They will help you design a proper sprinkler
sys.. Sounds like you need more valves / stations. Look for names like
Hunter or Irritrol or Hardy, or Richdel. These are good sprinkler parts.
Try this place to see what I mean about all this.
http://www.dripworksusa.com/
Good luck

"Frogleg" wrote in message
...
On 3 Jan 2004 16:16:33 -0800, (the insurance
guy) wrote:

I have installed a sprinkler system in my backyard and ran into some
problems.

You might try this in alt.home.repair if you don't get suitable
answers here.