I had this happen last week with PS. It is delivered through the HP gun so it was easy to find. The
flojet was cycling about once ever 5 minutes or so. (Like IB says) I went bay to bay and sure enough, one bay gave a burst of PS when started, so it was easy to find the culprit. Come to find out, it wasn't a bad solenoid, but a sliver of "Something" between the seat and plunger.
If its your FB system causing problems, you may have to pull lines to see which solenoid is leaking by. Unless its bad enough to push liquid all the way out to the FB.