Cannot understand this, mine are all in full flower, have you been cutting them back at all at the wrong time, they flower on the current years growth either in the ground or in pots. Early spring is the time to cut them back, then they have spring and early summer to make their growth.

Agree with Lizziebee's comments. Are they perfectly healthy otherwise? Nothing odd happening towards the end of the stems, where the flowers should be? If in pots, what are you feeding with and how often?

Until we know how you have looked after them it is difficult to give you a precise answer!

For example;

Are they in pots?
If so what size of pot?
Are they indoors or out?
How have you fed them?

I could ask more questions but let me suggest you look at this link to see how I treat mine, then if there is anything you feel you don't understand get back to us with a bit more information.

http://www.thegardenersalmanac.co.uk/Data/Fuchsia/Fuchsia.htm