99 jetta vr6 slow acceleration

It appears that you got a load of bad gas on top of an already marginal filter. Where do you buy your fuel? A single filling of gasoline from the dregs of a slow-sell station could explain everything.

Peter Wieck Wyncote, PA

When trying to purge bad gasoline, as a rule DO NOT add premium. The difference between low and high-test gasoline is ignition characteristics... premium is less explosive than regular, and may cause hard-starting. Add a can of Techron and fill with regular, try running that through the system. But the bottom line is that you may have plogged even the new filter if the Techron does not clear things up shortly.

By any chance, did you run the tank nearly empty at this fill? And go to US-Gas or some such on US13 vs. a name-brand station? When in Delaware, stick to Hess or WAWA if you are looking for discount gas. Delaware sells E10 Ethanol as a rule, and some of the slower-selling stations can be problematic.

Peter Wieck Wyncote, PA

Sure could. From both directions. A fouled plug or bad wire could cause poor accelleration and a fouled injector could do the same thing. See how Techron does for the injector, and consider replacing the plugs if they are at their ~30,000 mile limit.

Peter Wieck Wyncote, PA