This is a known problem with these conversions.  The power relay for the coil
isn't getting enough voltage when the engine is hot and isn't allowing the
engine to start.  Some folks have gotten around this problem by running a
larger wire from the battery to the relay with a push button so that they can
temporarily give the relay more juice to get the van to start.  And you
wonder why this conversion kit is no longer being sold :)  Hope this helps

Thanks,
Ken Wilford (right over the river in southern Jersey)
http://www.vanagain.com
John 3:16
Office (856)-765-1583
Shop (856)-327-0027
Fax   (856)-327-2242