Sounds like an incurable problem and I wouldn't waste any money looking for a fix. I feel for you, and to show my sympathy and how nice a guy I am, I am willing to take the Ventana off your hands...a straight out swap for my gasser. I know, I know, the offer is too much, but I am not kidding...you'll notice the improved ride and drive characteristics immediately.
You're lucky I am such a nice guy.