Actually each part is working as it should. I've mulled it over and what I think I'm feeling is rough guides and thread paths. When I raise the presser foot the tension disks are loose, when lowered they are snug together. So that part is working. When the machine sews the stitches are nicely made. So that part is good.
I think what I'm gonna do is put some polishing rouge on a piece of thread and boot lap the guides. I had to do that on a rusted machine once and it made a big improvement.
Joe