Help !

My 82 just got over a bout of completely dying on the highway. This
happened 6 or more times over a period of a couple of weeks until I was
able to  locate the problem. The double relay that powers the fuel
injection and fuel pump had a set of bad (intermittent) contacts which
caused loss of 12V power to the whole FI system. Sometimes I'd get 12V
other times I woiuld get 2V, 4V etc. Needless to say when the voltage
was low the van would die or not start.  Well I replaced the relay and
it's not dyin' anymore but it's running real rough and doesn't like to
accelerate one bit. I've checked the coil, air box (the Bentley manual
misleads you big time on how to measure this puppy) thermal sensors,
vacuum/centrifical advance, fuel pump regilator and replaced the points
rotor cap and plugs. Under load while accelerating it bucks like a
bronco. Once I get up to speed it's ok till I have to slow down and
speed up again. It sounds like it could have a vacuum leak somewhere
'cause its noisy but I haven't been able to find one. 

It's possible (maybee likely) that the problem is one of the things I've
already checked so don't be afraid to suggest something I said I checked
already!   

Any ideas out there?

Gary McEachern
'82/'84 Vanagons