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De-smogging questions....again??!!


Hodgepodge
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OK, here we go.....  

 

I'm preparing to remove all the smog stuff for my '75 2002 and have read through most if not all of the 15 years of forum pages here.  Many people talked of writing an article for it.  The information is mostly here, but it is just disjointed enough to be a challenge.  I'm getting ready to take the front of the engine compartment apart to flush the radiator, replace hoses, belts, clamps, water pump, alternator and several gaskets, so it seems like the right time to tackle the smog stuff.  I have bookmarked several of the pages here that provide schematics and images.  All good stuff.  

 

As it turns out, the previous/original owner of my car did not disconnect the emissions controls as his son-in-law believed.  The only thing that was disconnected was the cold air intake flapper valve. The air pump has a working belt on it. He did, however, replace the Solex carb with a Weber 2-barrel (surprise!).  Probably the smaller one.  I will know which one as soon as I get the rest of the grease off of it and take the filter off.  

 

Couple of questions that I could not find adequate-for-me answers for:  

 

1.  Intake manifold.  I'm good with the one I have but just need to cap off the EGR lines, correct?  It is the "Minorah" style

2. Exhaust manifold.  A lot of articles talk about using a Tii manifold.    I'm not finding those anywhere and I wouldn't expect to these days.  I was initially assuming that the catalytic converter (thermal reactor) was integral to the manifold like on my E39, but that does not appear to be the case.  I do see several ports and extra pipes, so I'm now thinking that those connect to the air pump.  Looks complicated and a little ugly.  I hate complicated.   Is there a header I can purchase?  Can I just cap off the ports....with ...something?  Suggestions?   I'm not opposed to replacing the entire exhaust system with a Borla, Anza, Monza, Magnaflow (Schnitzer....Dinan... :-) )  or similar system, perhaps in stainless steel?  I've done that before on other cars.   Does anyone make a complete kit for the 2002?   Any other ideas?  

3. Is there a simple way to keep the vacuum advance distributor, or should I just opt for the mechanical advance one? ....Where wold I get that from?  Are there any other options?  Now seems like the time to go electronic also.    

 

Perhaps the only thing nagging me about all this is that, as an old IT guy, I learned you should never alter more than one major system at a time.  That rule works great for cars, too.  But here I am messing with emissions, fuel delivery, exhaust and ignition in one project on a car I am not yet intimately familiar with.   

 

I will try to piece something together in terms of a how-to as I work through this.  Many people here have contributed to this topic, but it will take walking through it for real to completely get it.  

 

Thanks,

 

Scott

 

Edited by Hodgepodge
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1) intake manifold is fine. Just cap off anything that you open off to atmosphere. 

 

2) Given your last post, I would swap the thermal reactor for a shortie header in stainless and then aim for something stainless in rear of that. 

 

3) The vac advance distributor works fine with the Weber. There is a ported vac port at the base of the carb. Whether your distributor is any good or not remains to be seen. A 123 Tune replacement may suit you. Lots been written here about that. 

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You are on the right track, and wise to take a step at a time.

 

1) Absolutely, positively, without doubt or question...take off the thermal reactor!  This is nothing more than a "heat trap" bolted to your cylinder head, designed to burn off the extra gas that doesn't combust during the low-compression, lean mixture, poorly timed combustion cycles. It adds nothing to "pushing down the pistons for power". If your air pump is connected to this ( via check valve and pipe in front of the valve cover) you are increasing the heat by adding more air to the exhaust ports (like a bellows blowing on hot coals)...Nasty!.  At the rear of the thermal reactor is another connection to a pipe that runs across the back of the cylinder head, to a filter (bolted under the intake manifold) and then to a 2-stage EGR valve which puffs spent (inert) exhaust gas back into the intake manifold. Remove the pipe, filter, EGR valve and hose, and then cap or plug the spigot on the intake manifold. Your engine will love you for this!

2) Remove air pump and mounting bracket. Also remove the (gulp) control valve and plug the vacuum port on the intake manifold.

3) OK to keep the stock distributor. Only use the vacuum advance (spigot on the outside of the vacuum can) connected to a ported vacuum source (on the Solex or Weber carb). Disconnect the vacuum retard spigot (on the inside edge of the vacuum can). You should only have one vacuum line connected from a ported source to the advance spigot on the distributor. I found the best timing for my stock '76 motor is 25 degrees (the BB) @ 1500 rpm with 60 degree dwell.

4) Intake manifold: Keep stock if you run the Solex or upgrade to a 32/36 Weber. Make sure all water lines are connected to keep hot coolant flowing through the bottom of the manifold. Very important to keep the air/fuel mixture from the carb from condensing on a cold surface as it makes the 90 degree turn from the carb to the intake valves.

5) Check carefully for all sources of vacuum leaks and plug accordingly.

 

Once the basic plumbing (or de-plumbing) is done, then you can start removing the eletro- valves, speed relay, EGR and choke relays, temperature switches, and related wires (usually sheathed in a blue cover) to clean-up your engine compartment.

 

John

 

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I just desmogged my 75 2 months ago.  I was able to snag a tii manifold off ebay, but if i couldn't i would've used a shortie header.  To remove the thermal reactor, i ended up having to cut one of the pipes ( the one closest to the firewall) with a hacksaw (i tried to avoid this bug i was already frustrated trying to get it out).  Everything else was easy to unbolt and disconnect.

 

I'm an IT guy too and have little experience with working on a car this old.  But I went through with doing everything in one go.  Everything was connected so I just kept pulling stuff out.  I ended up having a car that wouldn't start. :)

 

I spent time "debugging" with the help of this forum.  It was a good learning experience.  The problem i ran into was this:  What i read was to pull the entire blue wire harness and everything with it.  I must've missed something, but that's not entirely true.  There are two wires you need to splice out and wire to come on with the ignition:

1.  The idle cutoff solenoid on the carb (had no fuel)

2.  Wire that goes to the coil pack (had no spark)

After i got those two hooked up, the car started.  It was pretty satisfying. :)

 

Anyway, hope that helps you a bit.  Good luck!

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1 hour ago, Simeon said:

1) intake manifold is fine. Just cap off anything that you open off to atmosphere. 

 

2) Given your last post, I would swap the thermal reactor for a shortie header in stainless and then aim for something stainless in rear of that. 

 

3) The vac advance distributor works fine with the Weber. There is a ported vac port at the base of the carb. Whether your distributor is any good or not remains to be seen. A 123 Tune replacement may suit you. Lots been written here about that. 

 

Wow.  Just looked and LOVE the 123 Tune, but I think I'll try to hook my distributor straight to the Weber first to avoid adding yet another variable.  The timing is already a little inconsistent on this engine, so it might be time to shell out for a new distributor anyway.  Dialing it in with a vacuum line sounds like a bit of a challenge though...   I also like the stainless shorty and related exhaust bits from Ireland Engineering.  Since the header mates to the stock down-tube, It looks like I can start  with the header and leave the stock exhaust on until the car goes to paint, which wont be for a couple of months at least.   

 

Thank you (and everyone else) for the great answers.  It is exactly what I needed to be able to move forward.   

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55 minutes ago, artichokie said:

I just desmogged my 75 2 months ago.  I was able to snag a tii manifold off ebay, but if i couldn't i would've used a shortie header.  To remove the thermal reactor, i ended up having to cut one of the pipes ( the one closest to the firewall) with a hacksaw (i tried to avoid this bug i was already frustrated trying to get it out).  Everything else was easy to unbolt and disconnect.

 

I'm an IT guy too and have little experience with working on a car this old.  But I went through with doing everything in one go.  Everything was connected so I just kept pulling stuff out.  I ended up having a car that wouldn't start. :)

 

I spent time "debugging" with the help of this forum.  It was a good learning experience.  The problem i ran into was this:  What i read was to pull the entire blue wire harness and everything with it.  I must've missed something, but that's not entirely true.  There are two wires you need to splice out and wire to come on with the ignition:

1.  The idle cutoff solenoid on the carb (had no fuel)

2.  Wire that goes to the coil pack (had no spark)

After i got those two hooked up, the car started.  It was pretty satisfying. :)

 

Anyway, hope that helps you a bit.  Good luck!

 

Thanks for the info.  Yes, it helps.  I saw about the wire from fuse 12 to the coil someplace but I did not know about the cutoff solenoid.  

 

I'm a bit older so these are the cars I drove when I was much younger and they were new or nearly new. The mid-70's was the beginning of a dark time for cars in general because of the embryonic electronics, emissions controls and the Government's CAFE requirements to get better mileage.  Go older and all you need is a timing light, a vacuum gauge and a stethoscope.  Go newer and the electronics starts getting easier to use.  Heck, there is very little I can't adjust on my other BMWs with the latest version of Ista-D.   Simeon pointed me to the 123-Tune distributors.  Bluetooth for managing timing advance?  Who'd a thunk it a few short years ago......  I gotta get me one of those.......  But not until I get much further down my fix-it list for this car.   :-)     

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2 hours ago, john02md said:

I think you'll find your distributor is vacuum retard.  Plug those ports.  You don't want to retard timing 

You might be able to find someone selling a tii manifold. 

 

John

Polaris 74

 

+1

 

’74 and later U.S.-spec cars had vacuum-retarded distributors originally.

 

Regards,

 

Steve

 

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27 minutes ago, Chimi562 said:

If you do plan to desmog. Please take pictures! It would be awesome if there is a write up with pictures. It would help so many people in the same situation as you are in.

I plan to. The only anomaly is that I already have a 32/36 Weber carb.  

 

 

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1 hour ago, Conserv said:

74 and later U.S.-spec cars had vacuum-retarded distributors originally.

 

Steve, doesn't your '76 have its original #164 Bosch, with vacuum advance ?

 

John's CA '76 has the original Adv/Rtd model, no?

 

I remember the photo you posted of the sales brochure, but maybe they goofed in that publication(?)

 

I am still confused.

Tom

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18 minutes ago, '76mintgrun'02 said:

John's CA '76 has the original Adv/Rtd model, no?

 

 

Yes, my original distributor has vacuum advance and retard...in addition to mechanical advance.

It is a Bosch JFU4, 0-231-176-059 

Stock distributor for a '76 California manual trans.

 

We should start a directory for all distributors used on all our models.   It should list stock displacement, compression ratio, carb type or injected (Tii), manual trans or automatic, cam, vacuum advance, retard, mechanical advance, timing spec, emission controls, regions, countries, or states designed for,...am I missing anything?.

 

Seems like everyone has a different model number, with different features....but we are all chasing the same goal...good ignition!

 

 

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