Even though it's becoming a common construction, it doesn't make sense to say, e.g., I'm going to try and do it. One doesn't "try and do something", one "tries to do something". The error becomes apparent in different tenses, where verb conjugation gives sentences entirely different meanings when "and" is thus used incorrectly.
Wrong: Billy tries and scores a goal.
Right: Billy tries to score a goal.
Wrong: I'm going to try and pass the class.
Right: I'm going to try to pass the class.
Wrong: Saddam tried and hid his weapons of mass destruction.
Right: Saddam tried to hide his weapons of mass destruction.
Wrong: We're all trying and doing our best.
Right: We're all trying to do our best.
&c. I often see this strange construction in official documents, journal articles, news reports, and obviously in everyday speech. I'm sure I've used it before myself (eek), but henceforth I'm going to try and not.
