Thanks for all of you that responded on the help with my 78 Bus.
Apparently this young couple is using this bus to tour every state in
the union except Alaska and Hawaii (for obvious reasons).  When they
left out of Washington state the bus was bucking like it is now.  They
say that it is getting worse lately that is why they brought it to me.
It feels like an ignition problem to me and I had a Vanagon that had bad
plug wires that did something similar.  I replaced the plug wires and it
still does it.  The plugs look great, they are not worn or fouled.  The
distributor cap and rotor look new but I am going to replace them today
just as a test.  I will check the AFM track as someone has taken this
off before and there is some tape holding it on.  I will also try
another ground to the engine just to be sure this isn't the problem.
The only other weird thing is that there are three ground connectors
under the center air box.  I could sware that I pulled off three
connectors from this however when I went to put things back I could only
find two wires to plug into it.  I am going to do the pin out test on
the ECU if I ignition tests out good.  The fuel filter is very recent
and didn't help.  I will also check fuel pressure at some point and the
distributor.  It has points but they look recent as well.  I will double
check them too.

Thanks for all the help.  If you think of anything else let me know.  I
will post back if/when I figure it out.

Thanks again,
Ken Wilford
John 3:16
www.vanagain.com