If the regulator leaks, fuel gets sucked into the intake manifold - it could mess up the mixture if enough gets spewed into there. The odds of this being the culprit aren't betting odds, but worth looking into, in my opinion. (can't hurt, and best of all, it's free)

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D