I have to second the advice on the coil.  My '65 MGB did exactly this, and I
dropped the fuel tank and had it cleaned, replaced the fuel pump, etc. and
finally installed a new coil out of desperation after about a year of this.
They are cheap and don't last forever, so give it a try before you get too
deep into it.  In my experience, heat related failures like this are due to
intermittent electrical connections cause by heat expansion.

Stuart
'85 Westy and other old cars

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Mike S
Sent: Thursday, May 17, 2012 5:59 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Questions/Advice Needed 1980 VW Westphalia

On 5/17/2012 7:54 PM, Gary Meier wrote:
> I'm having an intermittent problem with the above vehicle quitting
> while driving. Initially this was mainly when the engine had been
> working hard; i.e. prolonged climb at the low end of the RPM range.
> Now it's beginning to happen more frequently and under a variety of
> conditions. When it stops if you let it set for 10-15 minutes it
> restarts and drives fine for an undetermined period of time (now
> getting shorter). I've replaced the fuel pump, fuel filter and most of
> the hoses on the fuel and intake system. Any suggestions on where to
> look will be greatly appreciated.

Fuel, ignition, compression. I'll assume compression is good, since when it
runs, it runs. You've made some changes to fuel. Look toward ignition.
Perhaps the coil is getting weak when warm - it's getting warmer outside in
most areas, so that might explain why it's starting to happen more often.

It could also be the ECU. They're known to develop cold solder joints in old
age, which might be exacerbated by warm/cold cycles. But that involves a
soldering iron.