I just reinstalled my S/C after having it rebuilt. I've changed nothing else and on every startup after the car has been sitting for at least an hour, it idles rough for a few seconds and the exhaust smells like unburnt fuel. It clears up rather quickly. Other than that the car runs strong and doesn't throw any fault codes. The A/F reads 14.4 to 14.7 on idle. Any ideas here?