7890B/5977B Inlet pressure is cycling around the set point and won’t stabilize. Did normal maintenance activities to try to resolve the issue, but so far nothing has worked.

What type of inlet? What column is installed and configured in the software? How far up past the ferrule was the column installed? What ferrule was used on the column at the inlet? What ferrule was used on the column at the mass spectrometer's transferline?  Please share a screen capture of the configuration window or the contents of the acqmeth.txt file located underneath your method's subdirectory using Windows Explorer.  What inlet mode - split, splitless, pulsed split, pulsed splitless?  What carrier gas? What is the carrier gas supply pressure at the tank? What gas traps are installed in the line? Does the GC share carrier supply with other systems?  What inlet pressure?  What column flow? Split flow? Septum purge flow? Which liner is installed?  What were the normal maintenance activities that were performed?