Hey.. One of my accounts is 2 years old.. and everything is "rarely show due to low quality score". Its 0.27% quality score on the search network (3800 impressions), it was a test I made with this account a while back.. (Content network - 54K impressions / 4 clicks. From time to time I try to save the account with no success.. even though all is targeted + relevant text ads and quality landing pages... nothing / all I add to the account is getting the low quality score within a few minutes. What you think.. is it possible...?
Why do you want to save it? You'll have build up a bad history with it. Deplete the funds and abandon it. Then start a new one - this is 100% within googles rules. A fresh start may give you better QS from the off.
You won't save it. My account is also nearly 2 years old, my very first campaign was great. The next 5-10 campaigns were a bit hit and miss, a couple were profitable though. Since then, I've started a few more campaigns that all started to receive bad QS's, now everything I make just starts at 1/10. Can't save it. Sorry.
I've "saved" accounts before so I know it's possible. But if you want to start fresh, go ahead. Just learn why you are doing poorly because just repeating the same things will give you the same results. You may get a better QS at the beginning as PPCIcon suggests but that won't last if you don't improve from what you did before. This whether you use the same account or a new one.