Hello Mary,
Should not make any difference what stitch you are on, if the needle is hitting the raceway it is probably out of time, if the needle is hitting the needle plate then either the needle is in the wrong way or something else has gone wrong, put the stitch width on the widest and select zig zag and turn the balance wheel by hand and see if the needle moves side to side in the correct position as it should.
drivewithken
November 2009