Maybe, but I have followed the vacuum road as far as it goes. As I stated, the intake was completely re-sealed, all the air plumbing is new, injector seals are new, and vacuum fittings checked. No change in idle as carb cleaner is sprayed around common leak points.

And air valves do seem to be a popular replacement item, according to the parts guys.

__________________
Chuck Taylor
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