I ran a search on this and came up with nothing. Devilbis gun used only for water base after thorough cleaning started with severe spray pulsing. One possible problem is with the spray cap. ON each of the two prongs there are two vent holes. One on each side is plugged up hard and even soaking in acetone did not soften it. So I took a small drill and drilled it out, The back side was so thin, the drill went right thru.Is this what is causing the pulsing? IF so, I suppose I could take some epoxy and close the hole back up rather than buy a new one.