Chevron makes this killer fuel injector trearment. It is labeled
Professional Use Only - Not for retail sale. Running that through with a fuel filter swap and a general tuneup got rid of most of the off idle stumble that my Zetec had.
The cleaner is on the pricey side $12. (Ouch!) I picked it up from Checker, but since you are in FL, there probably aren't a whole lot of those around. Ask them at the counter, the store near me stores it in the commercial center, behind the counter. It comes in a black bottle.
