fx impact...powerless

checked breech seals etc.? I dont own an FX but I always start with the most simple seals, check them and work my way around the gun.

Barrel tight? With a chrony, have you tried different power levels to see if it changes?
on the other hand and maybe a good hand after a year-and-a-half two years is a good excuse to send your impact off to Esting Rowe and have him rebuild it and tune it. of course you could always Trade It.

JAM be from Slovenia.. 

Have a look at the end of the valve rod. Remove the valve adjuster and check the piece on the end of the rod hasn’t unwound. It should be as above No4

double post

Can you post a picture of the problem area, then i can tell you the size of the oring.

Oring is 2,9x1,78 PUR 90
Ernest’s makes a Delrin replacement which works better and lasts almost indefinitely (after thousands of shots mine still looks new) Worthwhile upgrade. 

Ernest [email protected]

JAM Don’t know if your interested but Ernest also usually includes the parts with his larger diameter titanium valve seat. Also has a great little tool to make removing/replacing the regulator much easier. 
Yeah so if you order his Valve seat you get all 3 items. 
Good luck with it. Michael