Steve-
I'll make comment on several points, in no particular order.  

First off, books.  I recommend 2:  
-Bosch Fuel Injection and Engine Management.  Charles Probst.
-How to Tune and Modify Bosch Fuel Injection.  Ben Watson.

Both are excellent and you really need both.  Probst is more theory, 
Watson more 'how-to'.

Secondly, throttle switches.  Ijust got done (like 15 minutes ago) 
with cleaning and adjusting those on my '87, among other duties.  You 
can check for operation by listening for a slight 'click' just as you 
move the throttle off idle.  have the engine off.  also, there is a 
convienient connector ontop the #4 intake manifold that you could put 
a continuity tester on to check this.  they do get gunked up and i 
took the throttle body off just to clean everything up real good.  
also cleaned carbon out of the throttle body and re-set the basic 
throttle valve position.  it is actually an easy job to get it off.  
i doubt the switches are whats causing you fits...

can you repeat the misfire while stationary and no load on the 
engine?  if you can, and the misfire seems rpm specific, you may have 
a bad air flow sensor.  this is actually pretty rare.  if the miss 
occurs only under load i would bet you have either moisture under the 
distributor or marginal plug wires.  engine washing could irritate 
either.  you may have moisture remaining in a connector somewhere 
too.  i've had fits after engine washing that go away after a day or 
two.  i now use low pressure washing combined  with Gunk use and some 
compressed air... no more fits after cleaning.

let me know if you want more detail on something.

-dan

Daniel Houg
Minnesota Department of Health
Internet Address:  fairwind@northernnet.com
Fax #:  218/755-3823