wopfe

I am working my way through replacing/refurbishing my whole k-jet system, part by part. Now looking at the cold start valve. I first thought i could buy a new one, but they are not cheap and not longer available from Bosch i think. My '79 euro manual car needs part number: 911 606 107 01. I was wondering since i have time enough at the moment if there is a good way of cleaning/refurbishing these yourself and test them?
Thanks upfront for the help.

Cheers!

Petza914

If you're talking about the auxiliary air valve ((AAV), the internal aperture should be open at room temperature (cold engine start). Supplying 12v should slowly close it (like over a 5 minute period) just as it would do as the car is running and warming up.

There's also the cold start injector that's at the front of the spider body. That plug gets 12v when the starter is cranking if the engine is cold. It knows its cold from the thermo switch down below the water bridge. It gets its fuel supply from a line that runs from the fuel distributor.

wopfe

Added some pictures i don't think this looks healthy