89 200tqw stalling & hard start

[Dave Aukerman]

Got a head scratcher here:

Car is a 89 200tqw dual-knock.

Car runs like a scalded cat at all times.  Stalls under decel.  Also, car
runs very rough under idle.  If car dies at idle and at times after coming
to a stop . . . no restart for a few minutes.

Swapped ISV for a known good.  No change.

Dumping codes both with car running -and- under no-start conditions gives
the 4444 code.

Any idea's?

Dave