From everything I have read the flap should actuate twice on startup, mine actuates once (which is one more that before I replaced the vacuum lines). maybe this is a quirk of an early E34? Mine is a German spec 1989, but most of what I have read covers the years the car was available in the US 91-94, maybe the German version is slightly different?. All that said when I do the throttle Blip test I don't see any motion from the actuator.For future readers, there is no need to buy used or reman'd units - we make a full actuator from 100% new parts all sourced in the USA, assembled in the USA, with some material upgrades over the OEM unit: https://www.angryasssolutions.com/parts/intake-actuator
We've sold near a dozen units, one to a BMW master technician at a US BMW dealer.
For the vacuum side, I'd hardly recommend a cheap auto parts store refurbishment - there is more to it than lines. We have you covered there too, with optional upgraded materials like modern braided vacuum line, and stainless steel fittings instead of BMW plastic: https://www.angryasssolutions.com/parts/s38-intake-system-vacuum-maintenance-kit
Gary, you are concerned that the valve inside the plenum is not actuating? This is based on the fact that the actuator only cycles once instead of twice?
Thanks for the web links you have some interesting products.