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Old 02-26-2015, 09:24 AM
dkmcgowan dkmcgowan is offline
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catalytic converter, air pumps, and a 79

I've tried to search for this but cannot figure out the exact answer. I know many catalytic converters have the air tube and get air from the air pump. I also know they will clog if they do not get this air over time.

I also know there was an air pump that went to a diverter and then to each exhaust manifold, as well as manifold vacuum to activate it.

I've also read about the 2 stage and 3 stage converters and differences.

I have the original diverter, bracket, and air pump from my 79. I see on the diverter the vacuum connection and then 3 large hose connections. One would go from the air pump, then the other two would go to each exhaust manifold from the diverter.

I don't see where anything would go from the air pump to the catalytic converter, but I read about this everywhere.

So I went onto RockAuto, and for a 79, the catalytic converter they list does not have an air tube.

So my questions are did the 79 catalytic converter originally have an air tube or did it get all it's air from the exhaust manifold? Also, I know you can get a newer 3 stage high flow catalytic converter with no air tube and pass emissions without the air pump, I've done it, but will that catalytic converter work as well and last or will it clog?

I've got my car back to pretty much stock everything except no air pump, air rails, or catalytic converter. I've been planning on at least putting back the catalytic converter. I want the catalytic converter to make it good with emissions, and don't mind burning off extra crap before it goes out the exhaust, and I like going stock, but don't really want to put back on the air pump and air rails, I would have to purchase a new pump, find a NOS diverter on ebay, new hoses, and purchase both air rails for the manifolds, that's a lot of money.
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Atlanta, GA
1979 Wagoneer
AMC 360 Quadra Trac w/low range 2bbl th400

http://www.ifsja.org/forums/vb/showthread.php?t=159324

Last edited by dkmcgowan : 02-26-2015 at 09:27 AM.
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  #2  
Old 02-26-2015, 09:34 AM
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jsinajeep jsinajeep is offline
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Your 79 did not have an air tube to the converter
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  #3  
Old 02-26-2015, 09:41 AM
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tgreese tgreese is online now
 
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The air pump to the convertor is a later design. I don't have a '79 TSM, but that is what you should have.

As I understand it, the air pump is needed with the cat because it introduces sufficient additional air so that the catalytic reaction (combustion!) can take place in the convertor. Without the air pump, your cat will be starved of O2 and won't have much effect. It's also possible that you can could damage the convertor by allowing HC residue to build up, rather than being burned.

Is there a cat that does not need an air pump? Seems unlikely, since the cat needs excess O2 to convert the unburned HCs to H20 and C02.

Even the '90 Wagoneer has an air pump. It shows air going to both the manifold distribution tubes and directly to the cat. I don't think you can get away from the air pump, if you want to run a convertor. http://oljeep.com/gw/vac/90/90-VacuumLayout.jpg
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Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
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Old 02-26-2015, 09:49 AM
dkmcgowan dkmcgowan is offline
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that all makes sense... I kept getting confused because I wasn't sure if in the early years the cat converter got enough O2 by the air tubes and air pump without a direct line to the converter.

I guess later they decided it needed even more O2 and added a 3rd valve directly on the converter chamber.

I have the 79 FSM and the section on the catalytic converter is two pages with no pictures and does not mention air tubes to the converter, nor does the air pump section, and also the diagrams in the 79 FSM are not as detailed, they are mainly just the engine and show lines going off page and say air pump but don't show the details.

That all makes sense...

I don't really have to do it right now, I will wait until I can do it all at once. You can still get all those pieces surprisingly.
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Atlanta, GA
1979 Wagoneer
AMC 360 Quadra Trac w/low range 2bbl th400

http://www.ifsja.org/forums/vb/showthread.php?t=159324

Last edited by dkmcgowan : 02-26-2015 at 09:52 AM.
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Old 02-26-2015, 09:49 AM
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tgreese tgreese is online now
 
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Interesting presentation here - http://144.162.92.233/faculty/mwhitt...17/cat_air.pdf

Apparently there exist electric AIR pumps, which one could retrofit to your application. You'd still need the injection tubes in the manifolds, the check valves, and some kind of diverter valve - possibley the one that's meant to work with the electric AIR pump.
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Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
ECO Green: '15 FCA Jeep Cherokee KL Trailhawk
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Old 02-26-2015, 09:58 AM
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babywag babywag is offline
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'79 did NOT have an air tube to the catalytic converter.

Newer catalytic converters don't require the air tube, most come with the tube plugged these days.
However if the vehicle had an air tube originally, smog testing may require it to be reconnected.

My '90 just went through smog, no air pump or related parts installed @ all.
TBI allows the removal of just about everything except EGR and vapor canister. Everything else is gone, no air pump, diverter valve, manifold tubes, etc.

Before and after printouts. http://www.ifsja.org/forums/vb/showthread.php?t=174546
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Old 02-26-2015, 10:27 AM
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TexasJ10 TexasJ10 is offline
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Quote:
Originally Posted by tgreese
Interesting presentation here - http://144.162.92.233/faculty/mwhitt...17/cat_air.pdf

Apparently there exist electric AIR pumps, which one could retrofit to your application. You'd still need the injection tubes in the manifolds, the check valves, and some kind of diverter valve - possibley the one that's meant to work with the electric AIR pump.

That's a useful link explaining the systems. Am I interpreting it correctly that later systems went with a three way converter that eliminated the need for air to be injected due to a new substance being added to the converter that could store oxygen and release when needed?
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* 1982 Laredo j-10, 360, 727, in rough shape and in the process of being rebuilt with 401, NV4500, Klune,
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  #8  
Old 02-26-2015, 12:12 PM
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tgreese tgreese is online now
 
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Quote:
Originally Posted by babywag
'79 did NOT have an air tube to the catalytic converter.
...

Agree. I meant the PO should have the TSM, not that he should have the air-tube convertor, if that's what you are responding to.
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Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
ECO Green: '15 FCA Jeep Cherokee KL Trailhawk
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  #9  
Old 02-26-2015, 12:15 PM
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tgreese tgreese is online now
 
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Quote:
Originally Posted by TexasJ10
That's a useful link explaining the systems. Am I interpreting it correctly that later systems went with a three way converter that eliminated the need for air to be injected due to a new substance being added to the converter that could store oxygen and release when needed?

Maybe. I don't know offhand. Not sure whether that refers to the air tube to the convertor itself, or means that the air tubes in the manifold are eliminated too.
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Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
ECO Green: '15 FCA Jeep Cherokee KL Trailhawk
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  #10  
Old 02-26-2015, 02:36 PM
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babywag babywag is offline
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Quote:
Originally Posted by tgreese
Agree. I meant the PO should have the TSM, not that he should have the air-tube convertor, if that's what you are responding to.

I was posting to let OP know '79 didn't have cat air tube.
I believe the '79 TSM can be had from oljeep.com
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  #11  
Old 02-26-2015, 02:56 PM
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Carnuck Carnuck is offline
 
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If you aren't in CA and just need to pass the sniffer test I'd look into Random Technologies high flow non-aerobic cat. AIR system is not needed with them and if CARB was recto-cranially challenged it would have an EO#.

http://www.ifsja.org/forums/vb/archi.../t-168455.html

http://www.randomtechnology.com/jeep.html

The AIR system was make-do antique rubbish. The carb had to be set rich from the factory to burn clean because the OEM cats couldn't ignite if there wasn't enough O2 or fuel.
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Old 02-27-2015, 11:30 AM
dkmcgowan dkmcgowan is offline
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So I just called MagnaFlow and Rand technologies, both said the same thing. The older cat converters did need the extra oxygen or they would not last as long, get too hot, and not burn as efficiently.

They both said with their universals without air tubes, they are designed to work with no additional oxygen. While extra oxygen would make them work more efficient possibly, they will work fine without the air pump, pass emissions, and last just as long.

They both said their models even with air tubes will run without it hooked up, the extra oxygen is good, but not required.
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1979 Wagoneer
AMC 360 Quadra Trac w/low range 2bbl th400

http://www.ifsja.org/forums/vb/showthread.php?t=159324
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