I have done my duty here in the drought stricken Los Angeles area and killed the lawn to conserve water. All the spray heads have been removed and the risers capped. The risers near trees and shrubs now have a drip manifold and drip system. The flow volume thru the existing anti-siphon automatic-timed 3/4" valves is much less. That seems to be affecting the way they work. The valves do not fully open. Some of them remain open after the solenoid has de-energized. This all seems to have started when the conversion to drip was done.

Are there different automatic valve mechanisms that I can install on the existing anti-siphon bodies that are made to work better for drip systems?