Mr Spears, you're explaining it right. first, toss out that number right after cranking. it's not reliable. the readings have to be at operating temperature and after a run. sitting in your driveway at an idle and "evaluating" isn't the right way to look at this. You need to take a test drive of varied rpms and then return to where you started and then note what you observed during the different rpm ranges. You say it was good until it sat for months.. have you checked for vacuum leaks? Or perhaps the pvc valve isn't "right" somehow? Is the air cleaner clear /clean and in the right place? Could a critter maybe have "moved in"??