Someone correct me if I'm wrong, and I can't check personally since I've pulled my auto box out to make room for an 01E, but isn't the input speed POST torque-converter, and thus would be 0 unless the output shaft is also turning? Or I suppose there could be a disconnect inside, i.e. transmission in neutral.. But either way if the input speed is 0 even in neutral with the engine running, it's got to be a bad sensor or else the torque converter isn't spinning the input shaft.

Assuming the sensor reading is accurate, it sounds like a disconnect between the engine and the transmission.. Or am I missing something here?