Kenmore Sewing Machine Needle Is Not Centered?

I have a Kenmore sewing machine, model 3851883506090. I've been trying to repair this machine. Initially it would not sew anything but a straight stitch in the left hand position.

In trying to fix this, the timing was effected and the needle started going too low and hitting the bottom of the shuttle. I adjusted the needle bar. Now the needle will move back and forth in zig zag, but when you go to straight stitch the needle goes to the right position. I can't find anything about this model except that Sears deliberately made their machines difficult to repair.