General: 850: Air filter connections, help needed!

[krolik]

After undertaking long overdue maintenance to my 'N' reg 850 auto I removed the air filter housing for cleaning. On the bulkhead side of it there are two pipes fitted to a valve. (just below main air sensor) One is white and goes to a module just below injectors, the other is black and goes to the underside of the air filter housing. Basically I forgot to mark which one goes to the upper connector (brass) and which goes to the lower connector (plastic) I know such things can be crucial on Volvo. Can anyone guide me on this and also tell me what all these pipes are for? With engine running they appear to create suction.
Similar to advance and retard on older distributor systems. I have looked in my Haynes manual from cover to cover but there is no mention of them or their function. I cleaned out the filter and housings and cleaned up the air inlet to engine, lubricated round and cleaned rotor arm and distributor, car starts a lot better but now maybe I mixed up these damn pipes, help please!

[jeff.warner]

Hi.
Does your car have the 20V engine? if it does (like mine)on the other side of the air filter box i.e. the side facing the front of the car, there should be a black hose that goes down to the air pump,below the battery tray, maybe this helps?

all the best.
Jeff.

[krolik]

Originally Posted by jeff.warner

Hi.
Does your car have the 20V engine? if it does (like mine)on the other side of the air filter box i.e. the side facing the front of the car, there should be a black hose that goes down to the air pump,below the battery tray, maybe this helps?

all the best.
Jeff.

Yes, the two small pipes I refer to are on the other side of the air filter box in the upper part, they go to some sort of valve held on by a clip...

Paul.