The only ethanol -related problem I have ever experienced is when it killed the original pump in my '56 Cadillac. It softened the original diaphragm causing it to expand.. This resulted in the volume of fuel pumped to be reduced by 1/2.
New, off the shelf pumps are absolute junk, however, pressure test your system to make sure your pump is actually the culprit.
Once you rule the pump out (or in) you can start looking at the carburetor.
