WWW.vanagonauts.com to get hold of the vanagon rescue squad. You will get
the best advice and help here.200+ members all over the country.Sounds like
you are going broke fast.Better get another AAA policy under another name
too.Is this your third tow so far?AAA should swear off vanagons.The
adventure you are having is in the breakdowns and the people you then
meet.Hope the senery is nice. If this stuff never happened with your old
moter, the problem is probably in the reinstallation of the components that
were reused.And probably in their connections.Dont know about the 1/2 tank
symptom.Cant imagin anything where a 1/2 tank would cause stumbeling.Can
you give the list anymore symptoms? Is it intermittant?Sounds like fuel
pressure to me.I would pinch the  fuel line with vice grips wrapped with a
cloth where the line leaves the fuel pressure regulator for the tank.This
will block the fuel returning to the tank and raise the fuel pressure(if
you have any).It may rev better then. With the vice grips installed, you
can do this and drive too.If it runs better then, it could be the
regulator.Check the vacuum hose that is attached to it.The part where it
works at idle and then starts stumbelling at speed,sounds like the pump is
not pumping enough gas to the injectors for them to inject at speed.At
idle, this gives the fuel system time to fill the fuel rail and hoses with
gas faster than it is used up. When you drive, the fuel is used quicker
than it can be replaced.Clogged filter? Clogged tank outlet sock?Ram a coat
hanger into the tank to tear off anynet or clog.Usually a fuel starvation
at these points result in a pump making noise very loudly.A starvation
after the pump,but before the injectors, does not do this.Good luck.