cam and lift pump

Hi fitted new lift pump this morning only to find it dont seem to be working... ie no resistance and even when engine is ticking over where you would normally feel it working against the cam there is nothing, is it possible that the cam is worn where it hits the lift pump arm and if this is the case can i just bypass and fit an electric one... Thanks for reading

if its working its working but when stood engine may need moving to get internal lever off cam ,its very unusual for cam on those to wear that much ,but not unussual for outer lever not to work even on some new ones