Sounds like the carb is messed up. Is this the original carb? With the vacuumn fuel pump boosted with an electric pump? Detach the fuel line going into the carb, there is a strainer at the carb, then if you are getting a full flow from the fuel line you need to pull the carb, remove the bowl and clean the fuel circuits and check that the float is floating and working the needle valve, also clean the jets in the bottom of the standpipe We have several carb gurus here on the chat site that can rebuild your carb if it is a good core.
This drawing from Keith Hardy's Old Car manual project.com web site, is of a 1927 carb, it is not identical to the 1928 but simular! 