Do you have any examples to explain consecutio temporum?

Well, consecutio temporum probably is one of the thoughest concepts to deal with for italian foreign learners. As the world says, consecutio temporum means "time consequence". With this we mean that every actions that happened in the past has some consequence in the present or future and this consequence is exepressed by verb tenses. 
Let's be a little be more clear: 

• Se avessi preso il treno, ora sarei già arrivato- 
  If I had taken the train, I would already be there. 
  With this sentence we express that some action done or  not in the past had a consequence on something that happenend later; so, that is why we have "Se avessi preso il treno" (action in the past that I didn't accomplish) "Ora sarei già arrivato" (consequence in the present for not being able to catch the train)