Do you put egg yolk in yours?  That's KEY.  Traditionally, carbonara sauce is basically just oil, pork (bacon, pancetta), egg yolk, black pepper and pecorino romano.  Personally, I like to make mine with heavy cream, bacon, egg yolk, garlic, shallots and a combination of pecorino romano and parmigiano reggiano.
Oh, and the pasta you're probaby thinking of is capellini.