Engine Performance problem
1987 Audi Quattro 6 cyl All Wheel Drive Manual 300000 miles

5000CS Quattro. Car has been sititng for past month. Started right up and ran fine but after about 10 minutes, began to chug to the extent that I had to drive on the shoulder. Seemd to improve a little as I drove further. Also, 5 year old fuel pump that has always been loud became even louder while running rough. When trying to start about 2 hours later, almost new battery comple tely drained. Jump started OK, drove to mechanic, battery dead again. Alternator checks out OK

sounds like the fuel pump may be jamming and draining the battery ..