Road tripped this last week in extremely hot weather -- we got stuck
in a 45 minute traffic jam on the 215 freeway, uphill in 110F heat.
Vehicles (many much newer than the vanagon) were dropping like
flies.   My 85, which has a new radiator, seemed to have no trouble
keeping the engine temperature down while moving.  So I got a little
smug.

Issue 1:  However, when we were in the stop & go traffic, eventually
something started to overheat.  The symptoms were a major loss of
power, and dying at idle.   Let the van cool down for about 45
minutes and it recovered completely.

My theory is that some electronics were overheating, rather than the
engine mechanicals proper.  I'm drawing this conclusion because the
temperature gauge never got that high, and these symptoms only
happened while in stop & go traffic.     At other times, the engine
water temperature hasbeen  higher w/o any of these symptoms, as long
as we were moving.

Issue 2:  Also, the interior of the van was getting a ton of heat
coming up through the floorboards, and through the passenger side
seat pedestal.  Looking at the underside of the van, it looks like it
has naked (uninsulated) rubber coolant hoses plus the exhaust from
the radiator both directly next to the (uninsulated) firewall.  No
wonder it gets hot in the cab!

Issue 3: I'm running a R134 conversion, which works well, until it
gets really really hot.  Then I can hear a relay in the dash tripping
and (I think) shutting off the compressor clutch.   Basically, when I
need it the most, the AC shuts off.  :(

Questions:

1. What is the most likely engine control electronic to overheat?  Is
this a replaceable part, or is stop-n-go traffic + 110F heat simply
outside the van's operating specs?

2. Is my van missing some insulation, and that's why I'm getting a
ton of heat in the cab?  Or did VW just design this poorly?   Has
anyone had luck with applying external insulation so the hot air from
the radiator doesn't soak through?

3. Is the AC shutdown w/R134 due to overpressure (I've heard that
R134 runs w/higher pressure).  Can I change out any parts, or do I
need to go back to R12 or try freeze12 or something?

thanks as always for sage advice!