I have a 1980 Vanagon Camper that has a Weber carb that was installed by the
previous owner. I am in the process of trying to pass the emissions test
here in Memphis, TN. I would not blame the carb, and it has been much easier 
for me to learn about and work on the carb than fooling with a FI system.
My advice would be to make sure that the jets installed in the carb fit the
displacement of your engine. My main problem turned out to be the engine 
running way too rich due to the idle jet size.

Joe Crumpton