Talon P wasting air

Need advice from the community. I bought a used Talon P with no external or internal mods…bare bome OEM. I filled it to 3000 and put 4 rounds down range. The power wheel was at 4. After the 4 rounds my bottle was down to 990.   So i filled the hottle back to 3000 and i bottomed the power wheel to 0. I put 4 rounds down range and same thing; down to 990. I dont have a chrony but the gun feels like it is shooting hot.

Any ideas how to remedy this?