I just got an exhaust backpressure tube in a junkyard to operate the 6PI, but there's one thing Im not sure about. What is that large rubber hose at the bottom of the picture? I know where it attatches and everything, but what does it do? I'm just wanting to know what everything does before I install it.

 

it looks like the air supply hose to/from your air pump. Look under your car you'll see a pipe that it connects to close to the motor. That hose looks like it goes from the cat to that pipe though.

 

The large hose is for a path for the air from the airpump to go to your catalytic converter when the Switching solenoid/valve decide it's time for air to go to the airpump from that source. That's mostly during times of acceleration and also when in fifth gear. In fifth gear the pressure is always going thru this hose to the catalytic converter. Again, in other gears its mostly during acceleration that this hose passes air to the catalytic converter. Its called the SPLIT AIR PIPE

The mushroom is a checkvalve to keep exausts gasses from going towards the intake manifold.

The tiny tube is for your auxillary port actuation. The exaust gas pressure on a series four uses this tube as a source of pressure for that purpose..

It's called the SPLIT AIR PIPE because at times the ACV splits the air from the airpump to two sources.....one is that pipe and the other is the PORT AIR. Port Air goes thru a intake manifold passage(s) thru the rear housings and to a hole at each exaust diffuser where it is dumped into the exaust PORT.

And that passage above about how it goes to the Port Air......is THE REASON you should not swap the front and rear rotor housing positions. As in put the front rotor housing where the rear housing is and vice versa.

 

Actually I dont have an air pump, but I dont think thats what it attatches to. It was actually connected into the back of the motor. Is this part of the emisions system, maybe? I forgot to take pictures of how it was installed in the car I got it from, but part of the large tube Im talking about is still attatched to my car, its just capped off. I'll get some pics of my engine bay posted.
Also, how do you post pics so they actually show up in the post, not just as links? Im sure its easy, but I couldnt figure it out.

 

Yes. It attaches to the back of the intake manifold. The airpump feeds air to the ACV. The ACV passes that air either to the PORT AIR as described in my first post (I heavily edited that post since you read it) or the SPLIT AIR PIPE(the thing in your picture).

As to the picture. I copied your link. Then I went to EDIT this last post. I then look at the top of the last post and where it says IMG, I clicked on it and pasted your link. The picture should show up after I'm thru. Practice it on your next post.

 

And as you know, on your series four the airpump and ACV are not required for backpressure from the exaust to operate your auxillary ports.

Before you connect this small pipe up to the feed line for your auxillary ports....do this: buy for a couple of bucks a long piece of vacuum hose from PepBoys. Attach it to the feed line to the aux ports. Blow like the devil in the hose. The aux port should retract. If they don't ...uggggh.

Here's a image:

 

So I dont need that tube at all, then, right? Since it doesnt allow exhaust to go up that tube in the first place, can I just kinda cover the hole over, or should I actually seal it shut just in case. The end coming from the intake is already sealed, obviously.

 

Notice how the very small pipe that feeds the auxillary actuators is b/t the checkvalve (mushroom device)??? and the exaust?? The exaust gas from the cat will go up the large pipe, then thru the small little pipe to feed the actuators. The exaust air will not get past the mushroom(checkvalve). Personally what I'd do is reconnect that large hose back up to the place that is blocked off on you intake manifold. That way it has a home, a place to be attached. It harms nothing when it's connected there. It's harmless. The checkvalve will act as a blocking device to keep exaust air from entering the intake manifold. Comprende?????

Hey, attach your link to your next post. You need the practice.

 

OOOPS. Serious error in this post. Forget it. Erased it.

 

Thanks for all the help. Sorry if it was taking a while, I've never seen what the setup was like originally and couldn't find an decent diagram of it. I was just making sure I understood how it worked because I didn't want to mess something up accedentally. Oh, heres a pic:

 

is that the fsm? I saw something interesting on there, what page is that?

 

That came out of a 87 factory service manual. It is in the FUEL section for the NonTurbo.

The Turbo is different.

 

Kick ***!! For the first time, the 6PI system is working. When I got it, the aux ports were wired open, then they were always closed. Now its all working correctly. I love it. Thanks again for the help.

 

best pic I've got showing the pipe

 

quote Hailers: "The tiny tube is for your auxillary port actuation. The exaust gas pressure on a series four uses this tube as a source of pressure for that purpose.."


I noticed oil is dripping from the tiny tube on my car. Would anyone know why or where it's coming from?

 

I just noticed that on my 86 NA that the little hose comming from the exhaust to the solenoids is not conencted. I have never noticed any power problems in the low range, so it didn't bother me. Now that I know it could be better than it is I was wondering (before I get the hose) what I should expect as far as perfromance in the low range?

Also, Last night I removed the 2 solenoids to see if I could actuate them with some low presure air. They both seem to. I also manually moved the arm that I assume directly rotates the ports themselves, they seem to move freely. My question is: Could I (assuming I want to "wire" the ports open) just leave the solenoids off and rotate the arm and keep it open? Mayeb this is what you guy do when this modification is done...

 

One more question:

It looks like in the picture above that there is some sort of brass plate. What is the piece that was removed? I am looking at the Haynes manual and my own car trying to identify the part. Is it the Air Control Valve that has been removed?

 

Just to clarify: On a previous post, I refered to a solenoid valve, what I meant was actuator (for the Aux port) But you guys probably knew that anyway...