Originally Posted by mrobinso
I have been watching this thread with interest, hoping you'll figure out the problem is a simple fix. People will probably laugh me out of the thread for this, but I would be remiss for not mentioning that you should check your battery terminal connections (assuming your battery isn't old and doesn't need to be replaced first). In my Limited corrosion to the battery terminal connections led to symptoms similar to what you are describing. I cleaned the connections and poof, car was turning over just fine.
Let me re-phrase slightly by saying that if its a battery issue, the car probably won't turn over at all, which is not the same as the symptoms you describe since it turned over and ran rough initially. Either way, worth checking if you haven't already. Good luck!