I recently installed an irrigation system in my backyard. 3/4 zones I added work perfectly when connected to the automatic controller. The fourth has me banging my head against a wall...

-Using the manual bleed, all the sprinklers in the zone pop-up great and perform as expected
-Using the manual knob of the solenoid, again, the sprinklers in the zone work great
-When I connect the solenoid wires to the controller and turn that zone on, only a few of the sprinklers pop-up and the ones that do only sort of pulse water. Also, there is a knocking sound at the valve.

I have verified the voltage at the valve is ~26V and I can hear the solenoid click on and off so I'm pretty sure the solenoid is good (also it's brand new).

At this point, I suspect it is a flow or pressure problem but I don't quite understand how it can still work manually but not by electrically activating the solenoid.

Any help would be greatly appreciated...