I managed to locate the problem. The wire running from the fuse block by the battery to the ECM relay is faulty. Once I bypassed the wire, the car ran fine. The wire would show voltage until the key turned on, then dropped to zero, indicating a bad connection somewhere. It seems unlikely I will find out where in the harness, so I have to run a new one. Given how the car is wired, I can't say I am surprised at this problem, but I am disappointed. Thanks to all those who responded, and I was very happy to find this site, it was a great resource.