As Ken already posted, could be any number or combination of problems
to cause these symptoms.
As already suggested:
TBS, O2 sensor, AMF etc.
I would add, TempII sensor, even if the symptoms persist when engine is
warm. When the engine is fully warmed-up the ECU still samples this
sensor.

Grounds are always suspect, when these symptoms are rearing their ugly
head.

One ground that is often overlooked is the main ECU ground. Located
(hidden)
behind the water tank. Real hard to see but if you use a bright light
and contort your body into a pretzel-like shape you can just see it by
looking
through the gap between the bed-storage-chest plywood frame and the
body.
Follow that? While looking at the ECU, the ground wire is to the rear
and right!
If it looks all rusty, check for continuity of course. To replace...
out comes
the bed, fresh-water cabinet and tank.... eeeeeck!
This Ground-Wire exits the ECU, separate from the Main ECU Cable if
memory serves
me right. Just enough wire to snip and slice-on an extension and
re-connect to say,
the Seat-Belt Bolt closest to the ECU. Save the OEM repair for a time
when you strip
out the interior for rust/insulation/mouse/paint/whatever
repair.....BTDT..... 8-)

Good hunting Chris

Phil Z.
'87 Westfaila
Campbell River, BC
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