After adjusting the action and string height, you should adjust the height of the pickups. If the pickups are too close to the strings, the magnetic field can cause undesirable distortion.Another by-product of a pickup being too close to the strings is that it can kill your sustain. The strong magnetic field will pull on the string causing it to stop vibrating prematurely. When checking the distance between the pickup and the string, always do so with the string pushed down at the last fret (the fret closest to the pickup). This is where the string will be the closest to the pickup. This is when you make your measurements and settings. Measure from the top of the pickup to the bottom of the string.