EGR, Smog, etc help needed!

[YoukaiMori]

I have currently hit a little bit of a wall in my repairs for my '78, the problem is that the previous owner or owners are the ones who handled the de-smog or EGR removal, and I'm finding that things seem to have been sort of... half-finished but without being able to physically see what the original state was like, I'm having trouble putting two and two together as to what should be fixed, removed, replaced, etc.

While changing the spark plugs I spent some time looking around this area, it does seem like they got the 4 plugs for the top part.


However, these four... pipes? Aren't these supposed to be welded or folded instead of just left open? Please correct me if I'm wrong.


That all being said, if anybody has some decent pictures of which parts should be removed or replaced that would be really appreciated. This is the downside to getting somebody else's project, is it's really hard to tell what they've actually done right and what I need to completely redo...

[18Fiatsandcounting]

The remnants of those 4 "pipes" that you show in the picture are what remains of the air injection system, otherwise known as the smog pump. Originally these would have been attached to a small manifold that was then connected through a one-way valve to the output of the smog pump. The idea was to pump air into the exhaust port right past the valve, and any unburn hydrocarbons (gas) would be burned since they are still hot. To be honest, this system does not hurt your performance that much, other than the 1/2 horsepower or so that it takes to turn the pump. What it does do, though, is clutter up your engine. As long as none of those 4 nipples are leaking exhaust gases from them, you can either leave them as is or try to find the right size plugs for them.

I can also see in the left of the first picture your EGR tube. This system feeds a little bit of exhaust gas back into the intake manifold, thereby reducing combustion temperatures and reducing the amount of NOx formed. (NOx is formed by the reaction of nitrogen and oxygen in the air at high temperatures) It has a small effect on performance, but similar to the air injection system, it clutters up the engine bay quite a bit

The other emissions devices that you probably have are a charcoal canister (EVAP system), and modifications to the carburetor, intake manifold, and ignition timing. The canister is worth keeping as there is no impact to performance and it minimizes the smell of gas around the engine. The biggest performance gains are to be found in better performing intake manifolds and carburetors.

-Bryan
PS: On cars this old, the air injection system and EGR systems almost never work, so if you don't have to pass a smog check, removal doesn't cause any issues. If you do have to pass a smog check, you would need to reinstall those systems and make sure they work (not always easy).

[YoukaiMori]

As long as none of those 4 nipples are leaking exhaust gases from them, you can either leave them as is or try to find the right size plugs for them.

This is what had me worried, when I was running some seafoam through and it was blowing white smoke as it does, I noticed some exhaust coming from those. I haven't been able to find anything about proper size plugs for these, do you have any idea? Or could I get away with folding over what's left of those and pinching them off and hoping for the best?

The charcoal canister is still there, but it's been disconnected, I've been thinking about reconnecting it.

[Nut124]

My -78 had the same smog stuff when I aquired it twenty some years ago.

I removed the air injection tube fittings and found round head copper rivets or something that fit upside down in the fitting.

I have never had them leak.

[Akspider]

My replacement engine was an 1800 from a '78 Spider and I used plugs similar to these: https://www.ebay.com/itm/173348528960?h ... SwV3Rfv3sV (If link doesn't work they're a M12x1.25 thread male brass countersunk hex plug) for the 4 injection tubes. Use a sealer on them. For the EGR fitting on the manifold I believe it's a M16x1.5 thread. Think I used a hex plug or oil plug for that too - gets all that tubing out of the way since no IM here.

[YoukaiMori]

Well I went ahead and ordered those, too bad it'll take a month and a half to get here, but that gives me time to try to figure out how to get those tubes out with how little space I've got to work with. Might just find a deeper socket for them...

[Nut124]

Search eBay for "round head rivet". Put these in the fitting upside down. They will seal on the head like the tubing flare did.

This port in not in the chamber, but in the ex port. Low pressure.

[YoukaiMori]

Well I found some plugs that fit, got some sealer and tried to get them in... they won't sit flush since they're a bit wide, and there's still an exhaust leak but we'll see if that gets fixed once the sealer cures.



At this point I may be waiting on my ebay order for another month before I really drive her much.

[18Fiatsandcounting]

Note that Midwest-Bayless sells the plugs you need:
https://www.midwest-bayless.com/p-9574- ... 5-new.aspx

More expensive than the ones from China, but you'll get them much sooner.
-Bryan

[YoukaiMori]

I appreciate all the help, I ended up grabbing those plugs off Midwest Bayless because I'm impatient. They stopped the exhaust leak at least!