amyjo,
When the controls do not produce the stitches they should it's a good indication there are some parts inside that are frozen up.
Use Tri-Flow and soak it all. Pay careful attention to the moving parts under the face plate and behind the control levers or knobs. Work all the controls as you oil the machine and if that is the problem, it should free up. You might have to use some heat, but check for plastic parts first.
Joe