1984 air suction system

[84sr54wd]

So, I just got my tercel and I am working on everything getting all the mechanical issues straight. I had to put on a new Catalytic converter due to mine being broken up inside and rattling. I ordered up one from Rockauto with the air tube since the original has an air tube. I installed the converter today but the pipe on the car that is connected to the original converter is much larger inside diameter than the little welded on pipe on this new Walker Converter....so for now I just shoved the small pipe in the larger tube of the car and bolted the converter up to both pipes. I have traced that air line up to under the hood and it looks like it passes through a bulbous looking black circular device (possibly an electric air pump?) right under the starter and above the driver's inner CV boot at the transmission. Then from there, it goes along the head of the engine and curves out right behind the A/C compressor and ends as an OPEN tube. Where is this supposed to go? If that black circular mechanism that the tube goes through is an electric air pump, then maybe this pipe originally went to a fender mounted filter or something where it acted as an inlet to the pump? I know there is no fan belt driven air pump on this car. Anyone know how this system works? I am tempted to just take off all the tubing under the car that is the air pump line and then crimp the tube on the converter and be done with it.

I was hoping someone could explain to me where this open tube behind my a/c compressor was supposed to go and how it all works. Looks to me like I am left with a partial air pump system?

[ARCHINSTL]

84sr54wd -
I edited the title of your post to reflect the correct name for this system.
The FSM is maddeningly brief on the Federal version of this system, consisting of just one diagram: See page EC-27 of the FSM (have you downloaded the FSM on this site?).

MORE than you ever wanted to know, with pix! See https://tercel4wd.com/forums/viewtopic.php? ... ion+system+ and the other links therein.
What I used was more Rube Goldberg than MacGyver, but it worked.

Also see https://tercel4wd.com/forums/viewtopic.php? ... ion+system+ for more incidental info - more never hurts, right? It is lengthy and not all pertains to our Gen II 4WDs, but is nonetheless informative.

ANYway - when I installed the new exhaust system back in 2012, since pre-1996 cars in MO no longer have to meet our emissions standards (particularly the extra stringent ones in the STL Metro area) and I'd already removed all save that air suction system...I just removed the system and found an appropriately-sized copper plumbing cap at Home Depot and secured it to the cat's little tube. As it was a little large, I had to drill holes and use a tiny bolt and nut; I also filled the gap with muffler cement.

OT, but the cat is starting to come apart at the seams, now being 9 years old. When it finally fails, I will go with some sort of "test pipe" - I don't want to fork out $80+++ for a new cat.
►►► Also OT, but - is anyone else running a "test pipe" in lieu of a cat? I know danzo used a flex pipe at one time, but removed it for ? reason. I just want to know if removing the cat gives the Terc some sort of weird sound.
Tom M.

[84sr54wd]

84sr54wd -
I edited the title of your post to reflect the correct name for this system.
The FSM is maddeningly brief on the Federal version of this system, consisting of just one diagram: See page EC-27 of the FSM (have you downloaded the FSM on this site?).

Hey there, thanks for the info....I ordered an FSM off ebay and it is not here yet. Where is it available on this site?

I looked at the diagrams you linked me out to, but I still cannot make 100% sure where the pipe behind my a/c compressor originally went to. Mine is an '84 wagon 4wd with M/T. It almost looks like it somehow connected to the breather on the valve cover?

[ARCHINSTL]

The FSM d/l is a sticky in the General and Repair Guides forums.
It used to be in the header of every forum, but that was changed sometime ago.
Here is the link: https://tercel4wd.com/forums/viewtopic.php?f=2&t=8103

Another help is the Repair Guide from AutoZone; it has real photos. See: http://www.autozone.com/autozone/repair ... deMain.jsp

Between the Toy and AZ manuals, they are better than any other. Period.

The tube under the compressor opens to the atmosphere. Look again at Petros' reply in the first link I quoted in my OP and then his reply in the first link of the quoted thread.
Tom M.

[Highlander]

I know that this is in the indexed posts, but...
The air suction system is a passive air injection system. The flat, pancake style thing attached to the bulbous one is a reed (or flapper) valve that only allows air to pass into the cat when the vacuum is high enough. The vacuum is generated by the Bernoulli effect of the exhaust gases flowing through the catalytic converter. The idea was to get air into the cat for the reaction without having another pump on the little 1450cc engine to rob power.

[irowiki]

Yeah the end of it on the engine side is open.

[84sr54wd]

The FSM d/l is a sticky in the General and Repair Guides forums.
It used to be in the header of every forum, but that was changed sometime ago.
Here is the link: https://tercel4wd.com/forums/viewtopic.php?f=2&t=8103

Another help is the Repair Guide from AutoZone; it has real photos. See: http://www.autozone.com/autozone/repair ... deMain.jsp

Between the Toy and AZ manuals, they are better than any other. Period.

The tube under the compressor opens to the atmosphere. Look again at Petros' reply in the first link I quoted in my OP and then his reply in the first link of the quoted thread.
Tom M.

Tom, thank you! I have gone back and re-read this and put it all together, my system is fully all there then. I just thought it odd that the pipe behind the compressor was supposed to be open. I am looking for a pump. Did not realize it used the exhaust gas flow to create an air draw. Makes sense and nice not to have a parasitic air pump drawing horses. Thanks again!

[84sr54wd]

I know that this is in the indexed posts, but...
The air suction system is a passive air injection system. The flat, pancake style thing attached to the bulbous one is a reed (or flapper) valve that only allows air to pass into the cat when the vacuum is high enough. The vacuum is generated by the Bernoulli effect of the exhaust gases flowing through the catalytic converter. The idea was to get air into the cat for the reaction without having another pump on the little 1450cc engine to rob power.

Thank you! Great info and exactly what i needed to understand the system. I don't think I am going to worry about the air tube on my new converter! Seal it up and be done.