Interesting that your problems comes when it is cold.  Most of us who
have had similar problems find that it happens when the engine is hot,
typically  when 2 hours down the hiway at the beginning of a long trip.
In these cases I have found that cleaning or replacing the solenoid is
only a temporary solution if it helps at all.
  The design is marginal to begin with; the long wire from the ignition
switch to the starter ensures that there will be a significant voltage
drop.  Things get worse as the contacts in the switch erode and the
connectors corrode.  The resistance of the wire in the solenoid coil is
higher when hot so I believe that this causes the problem to show up
most when the engine is very warm.
  The standard solution is to install a relay; a kit is supplied by at
least one of the list vendors.  I have put similar relays in a series of
my buses/vanagons: '76, '80, & '84, and I expect that one day I'll put
one in my '91.
  One point that is often overlooked is that the ground path for the
solenoid is thru the starter circuit itself.  If the brushes/commutator
are bad enough, even a good solenoid with relay won't activate.  For my
'84 I eventually had the starter rebuilt for $75.

Our family has many fond memories of parking on hills, getting everyone
out of the van (including Grandma) to push start, or crawling under with
a hammer.

Have fun,

Larry A.

Todd Last wrote:
>
> My van is getting persnickety about starting. Usually when it is cold it
> refuses to engage the starter.
> However, if I whack the side of the starter and solenoid, it will
> usually start afterwards - but not always.
> (I remembered this trick from having two previous air-cooled VWs.)
>
> I'm assuming that the solenoid is sticking. If I turn the battery gauge
> on the camper panel on, I get a green light - just nothing happens when
> I turn the key.
>
> Can I just take the solenoid out and clean it? Or is this just the
> beginning of starter failure? battery failure?
>
> Todd
> '88 Westy