Mike, I had a similar problem with my 380sl in the past. Cause was the fuel 'accumulator' and as you found out the book calls it a 'reservoir'. It is located next to the fuel pump and fuel filter and almost looks like another fuel filter. If I remember correctly, there was an input and an output connection. The 'output' end was rerouted back to the fuel tank. If you get gas at that end, then then the accumulator is probably bad as I believe it only routes gas back to the tank in that direction if the diaphragm in the accumulator leaks. Hope this helps you. bkim