LISTMEMBERS: (SORRY SO LONG BUT FULL HISTORY IS NEEDED)

I have an 86 Syncro that has always had (since I got it) some
bucking/bogging "Vanagon syndrome" type symptoms under very specific
circumstances For the past year whenever it rained I would
experience engine bucking or surging, no power meaning pushing down
on the gas pedal would result in nothing happening at all the RPMS
would not raise and the engine would stay bogged If I could get it
into 3rd gear and feather it up to about 3000 RPM it would clear out
and run fine Turning the engine off and restarting did not have any
real effect I had been told that this indicated an electrical issue
probably a loose ground I have never been able to find anything
loose, but as it only happened when it rained and I lived in SO CAL
it wasn�t that big of an issue

I have since moved from SO CAL to BOONE NC where wet weather is much
more of an issue Subsequently two weeks ago my symptoms changed
drastically - now in any weather the vehicle will start fine idle
well, after about 4 to 8 miles it will start bogging again push gas
to floor nothing happens at all no increase in RPM the engine just
stays bogged down As this happened on my way home from work I
decided to disconnect the AFM harness and see if it had any effect -
it did I was able to give the car gas it revved normally and
everything seemed fine So I drove it home like that, it drove OK
except I had to feather the gas pedal very carefully and experienced
a great loss in power on the steep hills

Two days ago a friend doing a Subaru conversion gave me a bunch of
parts including two used complete air boxes with AFM and harness I
immediately swapped one out for mine (the whole box) and am now
experiencing totally different symptoms again Now it idles great and
runs for about 10 miles no problem but after that starts dieing every
time I put in the clutch or come to a stop, if I restart it runs fine
again for about 2 minutes or so and then starts dieing again =20

As this is my daily driver I really need it to get back on the road
in a stable condition I am mechanically inclined and have pulled VW
air-cooled (63 Transporter and several bugs) motors and transmissions
before but am not very good with electrical I would appreciate any
advice on how to trouble shoot this correctly or where to go from
here

Again sorry for such a long post