After several nozzle failures I have a design that seems very robust and made several acceptable prints.
But then more trouble...
As far as the PLA goes I have now tried turning up the heat, down the heat, oiling the filament, manual feeding, adjusting the tension on the Wade's extruder, adjusting the current... But no luck after the initial success. The one good thing is that the new nozzle design has not fallen apart and seems very strong.
I have some more ABS so I plan to try adjusting the settings and seeing if I can get the ABS to extrude consistently. (Although I hate the smell and the warping issues with ABS, but I will live with them to diagnose my problem.)