Small pipe round the back of the block query

[rustyp]

There is a small pipe that attaches to the large pipe that goes from the air-box to the turbo round th back of the engine.

This little pipe which as I understand commonly breaks off goes to some solenoids and has a 1 way valve in-line.

Is the purpose of this pipe to allow a feed of filtered air or does it measure vacuum for the fueling?

If anyone can enlighten me as to it's purpose that would be great thanks, Russ

[321Away]

It doesnt measure anything, the sloenoids control idle speed,egr etc, more often than not the 1 way valve is gone, so not sure that its purpose isa essential, i (guessing here lol) thought that it maintained the vacuum in the solenoid circuit so that the car can adjust the idle speed before the vehicle is started and the vacuum built up, with bongo's when u turn the ignition on you can feel the accelerator pedal drop away from your foot by a fraction and i thought it was sthg to do with that?? like i said total guess,so probably wrong lol
Julian

[Northern Bongolow]

the pipe delivers a vaccum to the top of the pump,so when you put your foot down the vac increases and advances the pump via a diaphram on the top, this makes sure you always have a fuel reserve to accelerate.

thats my best guess .