Is it only fuel stavation or can lack of spark cause my uno to have difficulty in starting(she cranks, though)

The first time starting of the day she starts okay, but after she was used, she has difficulty in starting.I need to crank her a lot ( often it smells like its flooding, but not always), then starts(if i'm lucky), sometimes with a puff of black smoke. A new fuel pump and sparks were fitted, and a bend in the fuel line was fixed. It seems the problem was solved, but about 80km further, the same problem appeared