Much as I hate to say it, sometimes being a DIYer isn't all it's cracked
up to be.  At least not without all the cool tools, or at least access to
them.

I finally broke down and paid someone to check out the 81 Westy.  I had
already run compression tests and checked every voltage and resistance
reading associated with the FI.  Got Bosch to pony up a new ECU, the whole
nine yards, everything checked out.

Turned out that the #4 cylinder showed 22% leakage during the leak down
test. One cylinder showed 18%, two showed 16%.  Unplugging the lead to the
injector for #4 brought emissions right in line...argh!  Guides, most
likely.

I suppose I shouldn't complain.  Nothing a $650 head (for both) job won't
fix.  At least I know what has to be done now, which is a heck of a lot
further than I was a week ago.  Or a year ago, for that matter.

Seems to me that unplugging one injector at a time is the perfect way to
diagnose individual cylinder issues, for those so inclined, and with an
emissions analyzer.

Happy trails,

Jack