That is the best theory anyone has come up with - thanks.
The only issue is that it is so intermittent that it fits with some flakely electronic piece rather than plain old vacuum. I will give it a try, though.
My current theory is that I have a flakey injector and am getting a lean misfire.
This is driving me nuts - BMW has new 3-Series for $299 a month lease which is starting to look good compared to $200 a month in parts to try to fix this elusive problem. My biggest fear is that I will drop another few hundred and then find out it's the ECU.
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe