TM P90 Hopup Issue?

[DarkAngel]

Dispite my original intent to keep this stock, i couldnt help but add a few parts to my baby. First I started by replacing the bushings with metal ones, then i replaced the spring guide with a guarder v2 spring guide. I popped in a Systema V6 piston (Yes its the red crappy one, but i didnt have any other v6s laying around) and a guarder V2 piston head and a Guarder SP90 Spring. the Anti reversal latch is systema as well. Everything else is Bone stock. The first thing i noticed with the Guarder cylinder head (which i noticed when i first installed it on my m4) is that it didnt have a very good seal (it came with the full guarder kit) after i installed the piston/piston head/spring i hadnt had the opportunity to test it, but i soon replaced it with the stock spring/piston/piston head so that i had a working P90 again untill i get a replacement P90 performance kit. So here I am testing the p90 at my dad's house (which i have a test range setup) and i realized im having some sort of misfeed issue. I stripped down the hopup, checked the rubber (which is still intact, tho i plan to replace it soon with the guarder clear one) i set the hopup off (clear barrel) etc. But what seems to be happening is the first shot will be a dud (and itll sit inside the hopup), the second shot (assuming the first round is still in the hopup and hasnt rolled out of my barrel) will hit the 2nd shot and cause it to fly out. This happens wether in semi or full auto, which is why i dont suspect the timing of the loading nozzle, but im stripping it down as we speak to double check this. Does anyone have any insight or experience with a similar problem?

Edit : oh i also replaced the EG1000 with a Systema Turbo. After dissassembling the gearbox + hopup and reassembling it all, it seems to work a little better. It shoots consistant on semi auto, but on full auto, occasional rounds "drip" out of the barrel like a leaky faucet. At this point ive removed the stock TM hopup and replaced it with the clear Guarder Hopup (Which was a pain cause it seems like the guarder hopup sleeve is slightly too thick to fit, but with some silicone oil and considerable amount of effort, it went in). However it still seems to have the same issue, which leads me to rule out the hopup as being the cause of this problem. My conclusion at the moment is that perhaps the loading nozzle is not returning to battery as it should, causing the first shot to not be chambered properly when the piston fires. This would in effect blow all the air into the hopup unit and escape without forcing the round out, which would allow the 2nd shot to fill the gap and hit the first round.