Intermittent idle problem with 93 JGC

This is an annoying, intermittent idle problem with my
1993 Jeep Grand Cherokee (5.2L V8).

The engine will start just fine but the idle RPM will almost
immediately drop to zero with the engine of course stalling.

Giving extra gas in idle will not keep the engine running
for long. The RPMs swing up and down in a fight between
wanting to stall and the extra gas but it always stalls
out within a few seconds.

If I can get the transmission in drive and start moving
before the engine stalls, the engine behaves just fine
and I can drive as normally. Within a quarter
mile or so of running, I can even idle at standstill
with out problems.
However, if I turn off the engine, the idle problem will
very likely return immediately.

This problem is intermittent and it can go months with
no problems. When this problem occurs, it will
persist from one engine start to up to a few days.

I'm worried that one day soon I won't be able to get
it into drive and will be stuck.

Does this look like an idle flow sensor probelm?

Thanks for any help in this.