I had also concluded that since not one drop of old fuel has been pumped into the system, there's at least a chance that downstream of the pump will work ok, though I know the fuel itself in the lines etc. may have thickened some. And I'm prepared to replace the pump if necessary, but I'm surely going to disassemble it and check it out, replacing the filter while there, and test it, before giving up on it. Just call me a crazy optimist...