Your Gas Block needs to be perfectly level. Without the spring, Gas Plug installed - the Rod should be able to slide back and forth with gravity alone. Loosen the front screw completely, and the port screw a little and you will feel the Gas Plug loosen. Put oil on everything (just a wipe should do), inside the Rod Cup too. Use M-Pro-7 oil (easy to find), I prefer Gunslick oil. Lock down the port screw forcefully (this is the important one). Tighten the front screw a little more than hand tight (or until Gas Plug slides easy, stop if it gets sticky).