With a properly set up sprinkler system, NO grass should be dying. To troublshoot the issue -- 1. Make sure all heads are all spraying in the correct direction, not blocked/covered up, or broken (missing the nozzle, not popping up, ect). 2. Investigate increasing the time you water that particular zone -- pretty hot now, I had to double most of my zone times to keep the grass green. 3. Make sure the original install including correct "head to head" coverage of the area being watered... may need to add some more heads.