Thanks for the detailed TSB. This van was apparently driven on dusty country roads, and the vent system might well be plugged with dirt. I followed the hose back to the canister, where I see a mirror image of the diagram but more complex --the hose enters the canister at the left, then exits the other end into the separator, then on to a smaller electronic component ( the canister vent valve ?), then on to a rectangular black box, then out the hose that vents to the air. Guess I missed it but surely there's also a vacuum line back up to the engine?
I'm stumped at removing the plastic hose connector at the canister inlet ( my older E150 had no such ) -- is there a trick or special tool required? I bought the only manual I could find (Haynes), but it doesn't cover the evap system. Can you point me to a more detailed source of repair info for this van?
In the meantime I'll try straightening the kink in the filler hose.