Have a relatively low mileage (under 90k) U.S. market '92 SE with the VE30DE
and slushbox tranny.  Engine stated surging and stalling big time three
months ago, and has been progressively getting worse.  It's been looked at A
LOT since the problem started.  The DE's engine speed will go through
periods where it surges/hesitatates uncontrollably on acceleration--no
difference whether it's hard or soft-pedaled.  The engine will also
occasionally die on deceleration--i.e., when I lift off the gas pedal--and
will occasionally die at steady-state speed, which makes for grand fun on
the interstate.  It also will die at idle while in gear, and has on one or
two times died during idle when NOT in gear.  So far it's been to two Nissan
shops, and no fix appears to be in sight.

In the meantime, these are the things that have been ruled out as the cause:

- Coil packs (no visable cracks, and they--according to the last shop's
diagnosis--continue to send good signals back to the ECM)

- MAF sensor (new one was installed, no difference; fortunately they still
have the old one to put back in)

- Cam sensor (latest fix: new one was installed yesterday; I assume it
didn't fix anything because the shop was supposed to call back to tell me
the car's ready to pick up, which they didn't)

- Engine control relay (I replaced this myself on the advice from a Nissan
tech who had said this relay has been an infrequent problem in the past;
it's the green one in the relay box mounted next to the driver's side front
fender; the engine ran smoother for a while and didn't die as often, but a
nasty plastic buring smell started and last about a week, and stopped at the
same time the engine started acting up as it did before.  Think I may have
toasted that new relay, but I'm not sure)

- battery cable (replaced by the first shop I took the car to; no difference
whatsoever)

- fuel delivery system (as inspected and diagnosed by both Nissan shops
who've looked at the car)

The ECM/ECU/(whatever acronym it's known by) has not been entirely ruled
out, but according to the shop has only emitted an error code once when they
were backing the car into the service bay, but they've been unable to get it
to do it again.  I've been arguing with the shop on whether the fuel pump
really the culprit (they say they've thoroughly looked at it, and they can't
identify anything wrong).

One other thing I pointed out to the shop:  when the Nissan tech told me
about the control relay, he opened up the relay box to point out
specifically which relay it was.  As I was writing the part number off the
realy, we twisted the relay a bit as it was still connected to its port.
The first drive in the car immediately after this, the car RAN HORRIBLY
(rough, hesitant) for several minutes before finally smoothing out.  The
first thought that is really was the relay, but that proved untrue.  The
next thought it that it may be the connector and/or the cable that the relay
is connected to.  Has anyone else ever had issues with this connection that
have resulted in similar symptoms?

If not this, does anyone else have any ideas on what to look at next?