Sing,

Yes is my guess. You need to check your source pressure and flow(do you know how?). Secondly, check your head's design flow and pressure rating(found in their literature or on the internet). You are checking if the system design has a problem.

1. Make sure all your main valves to the system are fully open including your main water meter valve to your house.
2. Has this irrigation problem existed from day one?
3. Was this system designed and installed by you or a contractor?
4. Has your house experienced a change in pressure or flow recently?
5.Has someone recently worked on your house or irrigation water system?

Answer those question and we can start on the second phase of troubleshooting the problem. Aloha