To investigate the fuel starvation problem, I got under the car on Wednesday and checked the fuel pressure regulator. It looked ok - even when I took it apart. No blockages or anything else. I reassembled it and wound it all the way open. When I took the car out, it was just as bad as ever, if not worse. However, I'm even more certain than before that it's suffering from severe fuel starvation. The next step is to try replacing the fuel pump. I have an old pump that I know's not up to the job of properly running the car, but it would do as a temporary replacement test to see if the current pump is faulty.