It's very possible that scale, rust, etc., came loose during the installation of the new pump and is causing a problem with the zone valves on your irrigation system.
Most valves have either a "jar top" that unthreads to remove the top, or screws that hold the top on. Inside, you'll find a spring and a diaphragm. Sometimes scale will get into this diaphragm, and won't allow it to function properly. Pay attention to the spring when you remove the top and be sure to put it back just the way it came out. The diaphragm will probably stick to the bottom half of the valve. Peel up one side of it, and it will come loose so you can clean it.
Last, make sure you reinstall the lid in the same position that you found it. There's a tiny hole that the solenoid fits over.