TM SR16 M4 Air nozzle issue

[Razcal]

I am having some problems with my TM M4. It seems to fire most of the time, but dry fires (no bb comes out) often enough. I have stripped the gun down and really took a good look at it. I have done this a couple times before and know my way around. What seems to be happening is the air nozzle does not always reset itself all the way back to the correct starting position. It ends up blocking the feed for one or two trigger pulls, then resets itself properly again. I know this because i shine a flashlight up the feed and watch it happen when i dry fire the gun. This action happens in semi and full selections. What would be causing this, and how do I fix it? Any help would be greatly appreciated. Thanks in advance..

[Razcal]

I seem to have fixed my problem, in case anyone else has this issue this is what i did to solve the problem.
I had to completey tear down the gun and the mech box. ( dont do this unless you are comfortable with the internal workings )
At this point i noticed that not a thing was broken, cracked or looking suspicous. Banghead
I did notice alot of discolored (black) grease in the mech box and some small pieces of steel (probably wire from when i did a complete rewire of the gun) floating around inside aswell. Little amount of dirt too. I should say i am not the first owner of this gun, but it was supposed to be a virgin mech box. (some of the mech box screws were not uniform)
So i took out all the gears and the cylinder and cleaned all the crap and grease off them. I then cleaned the mech box itself. After that i regreased and put it all back together.
After a coulple of years of use i think a good cleaning was all that was needed.. My guess is the air nozzle movement was being hampered by small dirt particles stuck in the old grease. I have fielded this particular gun about 10 or 15 times, all stock and nothing has ever actually broken. Gotta love the TM.