what makes these open? Is it just the electric hookup or a combo of electric and vacuum? I reinstalled the JCW intake after the previous owner yanked it in favor of an aftermarket, and forgot to hook up the vacuum.

Wondering what the vacuum does. Is it the little skinny tube in the front/left part of airbox? The line is currently capped, no codes thrown.

 

I have mine disconnected (took the actuator off as well). Did so when I put a K&N on it. Pretty sure the vacuum from the engine is monitored by the ECU via the connection inside the air box. 4000 RPM and actuator pulls the flap open.

I don't get any codes.

 

The Vac line T's in by the bypass valve to provide vacuum to the actuator for the flap. But the electric solenoid controls if the vacuum moves the valve so you have to hook up both to make it work.
But honestly don't bother. Often the vacuum line pops off the bypass valve and makes a leak. And running it open all the time doesn't hurt it at all, and actually makes it sound a little better.

 

Why do you want to hook the thing back up?

 

the JCW intake or the vacuum? I want to get the flaps to function, which means hooking up vacuum.

The KN intake was gulping and hesitating at WOT.. also, I don't like oiling up the damn thing, so I replaced the paper JCW filter with an Amsoil.