Same thing would happen to me on my 4000 Quattro, it was the wires that went to the selonid. Cut them out, re-soldered in some new fresh wire, and have not had an issue ever since. This right here is reason # 243097548290750892475823475893475698073309 why standards are better than auto tranny cars, you can always just pop the clutch to get it going. hell, I drove around for about a year with a non working starter in one of my cars.