Accent LC (2000-05) :: Car Scavenges And Suffocates / OBD Not Working

My car is a 2004 Accent hatch, 1.6L manual.

I had a no-start on Friday morning, and discovered that the fuel pump had died. I tested it on its own, and it has not coming on. The relay was operational, and I had power at the pump, so I replaced the pump. The pump came on and the car started quickly and sounded perfect for about 3 seconds. Then it began fighting to stay alive, and finally starving out. It is acting very rich, belches some grey smoke, sounds like unburnt fuel is being exhausted. It stalls pretty hard, and the CEL comes on.

I connected my WiFi OBDii scanner and had a bummer of a time getting it to communicate with my iPhone, even though it has in the past. Finally got Dashcommand (app) to tell me: "Failed to read emissions monitor status. OBD-II communication error." After some excessive profanity, I connected an Innova scanner that has also worked on this car in the past. The scanner gets power, but never reads a code. The 'link' light flashes sporadically, and fails to read anything.

It's as if the initial start up phase is peachy, but it won't transition to normal operation. I assumed vacuum leak or purge valve nonsense, but I can't find anything disconnected or obviously amiss. Other than that, the fuel rail pressurizes, and the car will start. Giving throttle works as normal in the first 3 seconds of startup, but when it tries to transition, the throttle responds in a bizarre, delayed manner, and then makes it bog and die quicker than letting it suffocate on its own. Whatever happened took my original fuel pump with it, and it won't communicate via the OBD port at all.