If the car runs and drives fine I would leave the functioning emissions system intact. What's your MPG now and how much better are you shooting for? I can't help on the electrical components but I'm sure someone will know. Great looking car!

ski

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ski

Does the system doesn't pick up any signal downstream of the cat....would there be any harm/benefit in removing it?

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ski

The car does run but I wouldn't consider it dependable yet. I haven't driven it enough to know where it's at. I drive about 60 miles round trip a day and would like to be able to jump in it and go a couple times a week. I'm just looking to put a little time and money into this and make it right.

Would replacing all the EGR components in good working order be beneficial to economy? I would plan on using a simple set-up with a vacuum amplifier and a CCEGR switch.
I don't believe this has anything to do with the choke. After digging around more I believe this is the vacuum diagram for my set-up below. That would make this the vacuum solenoid valve. If that is the case what electrical signal is controlling this? As well as the idle stop solenoid?


According to the diagram above this switch would be the CCIE and the CCEGR would be on the radiator.

A catalytic converter in good condition does not restrict exhaust flow. If your cat (meow!) is internally melted or clogged, which is fairly likely, then yes, that'll be taking a large bite out of performance and economy.

If you're keeping the cat (meow!) get a № 912005 (replacement for previous № 712005). This is a California-spec converter, which means it is type-approved to a much tougher standard and has much higher catalyst loading than the cheapie non-California converters. Which, in turn, means it will work well and hold up well behind a dirty-running engine such as a Slant-6. Another good thing to do, exhaustwise, is to wrap the headpipe from manifold to catalytic converter with this stuff. That'll keep the exhaust heat in the pipe, which means it will not be heating up your underhood area (including intake air) and it also means the converter will have an easier time "eating" the dirty exhaust.

Speaking of exhaust: 2-1/4" headpipe = very good idea even on a daily driver. Muffler: This Jeep Cherokee item is a terrific pick: flows well and is designed to keep an inline-6 engine quiet, stainless steel construction, good price.

If you're keeping the EGR, you will need to keep the vacuum amplifier. I'd swap on an EGV-490 (less than $20 on super sale at RockAuto). This EGR valve bolts right in place, but has a pressure transducer that tailors the exhaust gas flow in much closer accord with the engine's workload, so you get the benefit of EGR without the mushy acceleration induced by excessive exhaust induction.

Elsewise, you're on the right track: delete the OSAC, keep the thermostatic air cleaner and charcoal can and PCV. Your finger is pointing to the idle enrichment vacuum hose, which connects to the carburetor's idle enrichment valve. No benefit from deleting this; it helps the car run better during cold start and shortly after.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Just to clarify a few things.

If I replace the cat the only benefit will be air quality?

The idle enrichment only needs a manifold vacuum source and the CCIE switch to operate?

If I replace and run an EGR all I need to do is run a manifold vacuum source to the orange lead in the diagram above and leave everything else as is?

I would like to remove the vacuum solenoid valve that feeds the amplifier and CCIE switch. Do the two timers pictured in the first post control this? I'm assuming they are the EGR and ETC timers. If I remove these timers will it effect anything else on the car? Mainly worried about ignition controls.

What controls the idle stop solenoid? How can I test its functionality?

The charcoal canister has been disconnected. Is there anything here to test, check, or replace?

Is there a procedure to test, check, or maintain the vacuum amplifier or thermostatic air cleaner system including the valve in the exhaust manifold?

Well, that's one reason to keep the cat (meow!). It's up to you, but air quality's not something to sneeze at (ahem). The converter makes the exhaust from your car a lot less noxious (poisonous and smelly) and deleting it is not really a good-citizen thing to do; everyone has to breathe what comes out of your car, and making a car pollute more than it should gives old-car owners a bad name: sooner than later someone stuck in traffic behind you, cursing you up one side and down the other because your car's exhaust stinks, is going to be in a position of power to do something about it with one of the periodic get-old-cars-off-the-roads initiatives we car hobbyists have to fight off.

There are other good reasons to have a good working cat (meow!) in place.
Even forty-one years after the catalytic converter first appeared, we still have knuckledraggers babbling in ignorance about all the (imaginary) backpressure they claim is caused by a catalytic converter, even in good shape. That's just flatly not the case. Nor is there any sense or sensibility in their claim that you can or should remove the converter because the car doesn't have to pass an emissions test. For one thing, it's still a federal crime to remove a converter from a car originally equipped except for the purpose of installing another converter. No, you will probably not get a knock on the door from any federal catalytic converter police or anything like that...how do you feel about breaking a reasonable, public-spirited law even if you'd probably get away with it? The catalytic converter was put there to make your car's exhaust less poisonous. It wasn't put there so the car would pass an emissions test every year -- it's the other way around, emissions tests are to make sure some putz at the exhaust shop hasn't gutted or removed the catalytic converter. Old cars in many places get exempted from emissions tests because they're mostly in the hands of collectors who don't drive them very much.
True.
Well, no, you wouldn't want to be removing bits and parts of the EGR system. It's a system: either have it all present or remove all of it. If you really have a bee in your bonnet to re-engineer the system, see here.
Why?
See here, except the can recommended in that article is no longer available, so use this one. Purge valve, if you want or need one (see linked article) is this one.
It's a no-maintenance item; either it works or it doesn't. Function is described here. Thermostatic air cleaner, manifold heat control valve: covered in the three books described in this thread.

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Too many people who were born on third base actually believe they've hit a triple.

The way I see it the vacuum solenoid valve is controlled by the EGR and ETC timers. Both of which are becoming obsolete parts. Looking at the circled section of the diagram below it appears that the vacuum solenoid valve just controls when the amplifier receives manifold vacuum. Looking at other vacuum diagrams the amplifier is ran directly to manifold vacuum. And the CCIE plumbing is on the manifold side of the switch so it does not effect this at all. They way I look at it is if I leave these components be or try to get them in good working order it is 3 more things to worry about. Two electrical and one mechanical device to worry about failing, as well as the wiring in between. I am looking to make this the most economical and reliable that I can with what I have to work with, without making extreme changes to the motor and such.

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Ah, gotchya. That makes sense. Well, OK then -- update to the transducer-equipped EGR valve as previously linked, and see here for how to put together an EGR control system that does not involve the solenoid or timers. Adapt the instructions at that page to account for the fact that your carb has venturi vacuum signal for EGR (keep that and the vacuum amplifier intact -- just use the temperature-sensitive switches described in the article to replace the three failing components on your car). Disregard the charcoal can hookup info on that linked page; you're already all set there.

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Too many people who were born on third base actually believe they've hit a triple.

Wow!

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

???

(???) Wow, this is an awesome web site,as proven by this very hands-on explanation of the mid-70's EPA controls system. Thanks Dan, D.I. & ski!

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

Picture number 4 is catalytic protection system. See this post, http://slantsix.org/forum/viewtopic.php ... 285840209f

Does anyone know why there are a couple of blank posts at the beginning of this thread? I needed to look back at it to get some more information from it. Anyway to recover this?