I have a 90 n/a and i'm pretty sure there is no air pump right now (i think the acv is gone too?). I don't know when it was removed by the previous owner. I've been doing searches as much as I can and have read that the air pump is needed to activate the 5th and 6th ports. I'm fairly new to the 7 and so I'm still not clear as to what all that means. Can someone point in the direction of a good explanation of how the 5th and 6th port thing, VDI etc.. works? And put simply, what are the consequence of running without the air pump?

Oh and how difficult/expensive would it be to get that stuff back in? What parts would I need?

Thanks in advance.
-Hen3ry

 

bump

 

I am sure you can get a used air pump for dirt cheap on here... The 5th and 6th ports open at about 3800 rpm.

That all the info I have I don't know much about the VDI and such.

 

on the s5 , the airpump suplies air that goes to through the ACV to the solenoids ( which are ecu controled) . from the solenoids the air is route to the 5th and 6th ports actuators and for the VDI.

the actuators are conected to sleeves that go in the motor. about 3800 or 3500, dont remember which, they rotate letting more air inside the chamber.

the vdi in the upper intake manifold , rotates too, at certain rpm and creates pressure?? or turbulence ?? in the UIM.

well, all this is clearly explained with pictures in the FSM.

 

thanks for the replys.
i'll take a look at the fsm.
so opening the ports up -> more air -> more power at higher rpms?
how much power would i lose by not having that whole mechanism intact?