Diagnosing the PullGrip
The grip is not normally a factor with a pull.
Make sure you are not aiming too far left, or that your shoulders are pointing too far left.
You might have the ball too far forward in your stance. This causes you to catch the ball when the club is swinging back to the left.
The club is likely being pushed outside the target line on the way back. The club should track a gentle arc on the way back. The club should be over your shoulder at the top, not over your head.
Your arms are likely pushing away from your body at the transition. Keep your arms in so that they pass close to the right pants pocket on the approach. Make sure your head doesn't move toward the target until after impact.
Video: What causes a pull?