After about a year of tracing down contact corrosion, hall senders, O2 sensors, AFM, fuel pressure etc. , my problem is fixed. 83-85 vanagons have an idle-stabilizer. They cause strange stalling problems often intermittent.
T.L.C Autowerks near Albany NY found it; something a number of Volks Dealers as well as myself could not. I highly recommend them. - 85 Westy "Folly"