:-D

Removing the vaccum hose will cause the engine to advance the ignition timing less, causing the combustion temps to fall. The result is that hydrocarbons and carbon monoxide are still in spec, but the cooler combustion will reduce the NOx.

For stumbling, I'd very much wonder about some sort of fuel delivery, ignition, or vaccum problem. You've covered the igniton stuff, but I'd still try driving around with the hose disconnected see if that helps.

As for the computer requiring a steady engine speed.. that's mildly insane as I see it. I'm sure glad I didn't have to jump through that many hoops. Hell the guy was patient enough to wait until the idle valve decided to act normal again and the DMV hooked up exhaust gas analyzer ended the test once the car passed.

- alex

'85 244 Turbo
'84 245 Turbo