Shawn -

Another possible area for this problem, (I've had it in the past), is in the
O2 sensor connection.  If moisture gets in there, you can develop the
hesitation/lurching symptoms similar to the ones caused by the AFM (and
usually correctable with the add-on short-wire harness).

I cleaned and dried my O2 sensor connection and sealed it in plastic and
insulating cover (split flexible plastic tubing).

Problem went away . . . about 30K miles ago.

Hope this helps.

Sam
'89 & '91 Carats