have a peek at the pic on this page
see if you know what it is...
I know it's a vacuum thingy, but what does it do?
how should I figure out how to adjust it?
actually I once mistakenly thought it would control the idle speed but
it ain't that simple, and she idles a little wobbly (always has)
Basically I'm just trying to get this old girl to idle a bit smoother
she is idling at 800 rpm, which is the recommended speed
new plugs, new leads, air filter ok
it's a 1985 520i L-Jetronic E28 FUEL INJECTED