Something I don't understand, if my plenum is open to the bottle why does it not degas when take the bottle off? And the remaining gas does not come out when I dry fire the gun, it remains under pressure and shoots extremely slowly even though the plenum is showing 170 bar reg pressure? Like the hammer cant bang the plenum open enough to get the gas out and it will keep doing that for about five shots that then follow a speed curve with the fastest shot at shout four and then it finally degasses like it should. The high pressure making it so the hammer cant open the valve enough seems to fit with the multiple degas shots but with the plenum open to the bottle why does the plenum start loosing pressure when I remove the bottle. I let it sit like that for an hour and it did not move, stayed rock solid at 150 at the time.
I just really wish I knew what I was looking for before I pull the whole reg so I have a better idea of what I am looking for. I prefer to do the research once so I only have to take everything apart the once but I have not been able to figure out a logical point of failure that would give this set of, for lack of a better word, symptoms.
Hi etothen. I have questions for you. There are pieces of information missing from what you've described that I need to help diagnose the problem.
First of all, are you sure you have an FX AMP regulator in that impact? If it's a HUMA regulator, then I can't help.
Assuming that it's an FX AMP regulator:
There are places where you mention what the plenum pressure was, but you do not mention what the tank pressure was.
For example, you said you increased the regulator pressure and the plenum pressure jumped up to 150 bar, but you didn't say what the tank pressure was at that time. If the tank pressure was also 150 bar at that time, then you may have actually set the regulator to some unknown amount above 150, but that's all the tank had in it at the time. If that was the case, then the regulator was doing exactly what it should do.
Another example is where you say the plenum pressure was 170 bar, but you didn't say what the tank pressure was at the time. If the tank pressure was, for example, at 200 bar, then that would indicate that the regulator is set to 170 bar and the regulator is doing what it's supposed to do.
Your observation that a high plenum pressure and a weak hammer setting is normal in that it would take several dry fires to finally drop the plenum pressure enough below the regulator set pressure to allow the piston to back away from the tiny hole in the end of the set screw and let air from the plenum to escape out to where the bottle connects to. This is normal behavior for an AMP regulator.
Your observation that when you removed the bottle tank, the plenum pressure didn't bleed out right away -- it required dry firing to drop the plenum pressure below the pressure that the regulator was set for. This is normal behavior for an FX AMP regulator.
Initially you said that you thought you were having a similar problem to that of the original poster, but this doesn't sound like the same symptoms. So far it sounds like your regulator is working as it should.
I did say that, IF the only problem with an FX AMP regulator was bad set screw O-rings, then you could bleed the air from the rifle and remove the set screw and replace just those two O-rings and re-install the set screw to fix the problem without needing to remove the entire regulator housing -- and that is STILL true. But I'm not saying there is anything wrong with your set screw O-rings -- so far, I just don't have proof that the O-rings are bad.
If you have more info that would help with a diagnosis, let us know. Cheers.
stovepipe
