It was the Distributor

Look carefully at the spring sizes - they are different

IT WAS THE REBUILT DISTRIBUTOR ALL ALONG

BAD - BUS DEPOT - BAD

The last time the Terpvan ran well was with the loaner distributor from Va. Beach Fred. Since his distributor fixed the problem, I ordered a rebuilt from Bus Depot in Pennsylvania, the Christian guy.
After install, the van ran but never well. It would idle and run at wide open throttle, but would have bad hesitation off idle. If you stomped on the accelerator, it ran but it was annoying.

I looked everywhere but the distributor for about two years. Air flow meter, fuel pressure regulator, injectors, fuel pump, computer, coil, grounds, caps and rotors, plugs and wires, compression and valves. Nothing fixed the problem.

When I finally opened up the distributor and saw the two different sized springs on the centrifugal advance. It was clear. There was very little resistance so as soon as the distrubtor started to spin and the vac retard was off, it went full advance and ran poorly until the revs were up to 2K+. I compared the resistance of the VW rotor to the resistance on the Range Rover rotor and it became more obvious.

That is one of the joys of wrenching. When the harmonic convergence of all your mechanical meditations reveal the path to enlightenment, smooth running and better gas mileage right before you.

Bus Depot was no help at all. They did not even offer to send me the correct spring or even tell me where the springs come from.

I used needle nose pliers to bend the loose spring into a shorter span so that it would engage.

WOW, that problem fixed after two frustrating years.

Of course, fix one problem and others pop up but take nothing for granted and do not assume anything is working correctly.  Never say, "well it can't be the widget," I just put that in, unless you test and verify.