Could be that the lie angle on your 8 is out of whack and not so with the other clubs. Put a piece of black tape on the sole of your 8 and hit 5 balls on the range mat. Now flip the club over and look at where the tape is worn. if it is prdominately near the toe or the heel then the lie angle is not set up to your swing. You can get it tested and bent at a pro clubmakers.