Porsche Enthusiasts Club Forum

I cracked a few vacuum pipes in the process of re-fitting my cylinder head. They were v.old and brittle. While taking it all appart I was trying to work out what it all does.



What is the electronic device that sits between the air intake pipe and the manifold. Is that path the air bypass for when the engine is idling?

I guess the other path is just there to create a vacuum for the brake servo.

Anyone interested in buying any of the vacuum pipes. I'm getting two of them made for my car but I can get any of them made easily enough. The spec will easily match the manufacturers spec. I could even get a full kit of vacuum hoses made should people be interested.

Tom

Yup idle control valve under the inlet manifold. Other circuits are Brake servo, heater control system & the carbon recirc system under the n/s wing.

On the brake vacuum line should air be able to go straight through from the big pipe to the manifold. It would seem to me that for controlling idle correctly the only path for air to get to the manifold should be through that idle control valve. On my engine air can go straight through the brake vacuum pipe valve to the manifold. Only the flow of air to and from the brake servo itself is one way.

My engine wouldnt idle properly when i put it back together and i assumed it was due to the cracked pipes.

Edit: saying that it seems unlikely that valve would have been damaged during the rebuild.