sewmom,
Mode 2 stitch 11 is the very same as Mode 1 stitch 1 if you were unaware. As for the presser foot tension, they both recommend 3 not 1. Your stitch reg. was ok at between 2-6.
Take your throat plate off, take your bobbin and holder out and check for any problems. Even a minute piece of thread will cause problems.
Last nite I had real problems and found the bobbin holder was faulty and causing the problem. Had to order a new one today.
Check your needle to be sure it is in correctly, flat side of the needle to the rear, needle size is correct, screw for needle is tight, make sure the foot holder screw is tight,were the feed dogs accidently dropped?
I just scanned these three pages on tension into another forum here for another member as she was having issues with her tension. If you have your manual handy, check it. Mine is well used. I refer to it constantly because I don't want problems. Good luck.