How about a leaking fuel pump check valve? I had one in the shop on Saturday that was pretty darn similar to your description and had similar mileage. If you have no pressure guages you could try just cracking the fuel line and seeing if it sprays out or if you have no rest pressure. The idea is that it should hold rest pressure for as long as it takes the car to cool down enough for the cold start cycle to take over. In reality it should hold rest pressure darn near indefinitely. Remember though it can leak down back through the fuel pressure regulator as well.