FX Impact M3 leaks out barrel

My M3 leaks out the barrel from about 230 down to 200 or so. It shoots well and at a certain point it will usually stop by itself. More recently this past Saturday while shooting a 100 yd match, it would make a light pop sound,like a little burp and be leaking out the barrel. Accuracy doesn't seem to suffer as I had two groups of 5 shots in the ten ring and nothing worse than 8, even missed one shot and scored 447\500.
Now, if I close the valve adjustment to zero, the leak will stop. Sometimes this tops it even after I open the valve to almost 4 open, other times, it just starts leaking again. I have replaced all the O rings and the valve rod and seat as well with no improvment. I did recently add oil thru filling air plus a couple small drops into the breach. I even removed second reg gauge and put in a couple small drops of oil just to see if it would solve the problem. I can't say for sure this helped or not. If it did, it was short lived. Any ideas?
 
This may help.

Thanks foe the info. I have already performed these steps to replace the valve and seat along with all related o rings. The problem seems to be related to the rod sticking for some reason in the bore it travels thru. The key being that I can shut off the air lk by closing the air valve adjustment to zero.
 
If you’re getting a puff of air the 2 x 1 tiny o ring at the mag slot end of the valve rod let go, or hot nicked from overtravel. Are you using the lighter valve spring from the slug power kit? The reason the leak lessens is by closing off the valve knob you’re just shoving that end of the valve rod deep into its cavity and the compromised o ring on that end is kind of “tamed “ for a bit, but it won’t be long and it’ll give.

Prepare for another disassembly. Have it back together within two hours or more leaks will arise(just my experience with working on impacts)