[robert.hatchett]

Sounds like the stored air is not able to pass through the regulator at the speed your unregulated test was able to provide.

This is a function of Cv through the regulator.

Unfortunately, since you are required to use the KoP regulator you may have to rework your design to compensate. Also unfortunately, there is no easy solution to this and may require a revisit to your design.

If you could post more details about your system, perhaps there might be more insightful answers to your problem.