Pulled the cover plate off, manually turned the hand wheel to see how things were moving - and the hook was pushing the needle as it was going by. EEEK!
The Pfaff 'manual' really bites - terrible pictures, photos out of order (photo 31 is at the beginning of the section, before photo 28). The whole section is really awful and I couldn't make head nor tail of what I needed to do.
Like washing machines, fridges etc, lots of brands are actually only made by one manufacturer - my Pfaff Grand Quilter 18.8 is the same as a Viking and a Husqvarna and the Tin Lizzie.
I *DID* find a really good YouTube video of technicians working on a TinLizzy - 2 parts:
OK - now this makes sense Went back to my machine, tested how things should be meshing, repositioned the needle, moved the hook a smidge, and it's good to go. YAY!
And happily can report that it's sewing away on 2 more comfort quilts - I load 2 at a time on wide backing. Whew!