Pros and Cons of Desmogging all original FJ40

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Been thinking (just thinking at this point) about possibly desmogging my 1981 factory original FJ for the sole purpose of it running better and maybe (dare I say) a bit stronger. I keep going back to the idea that I have a perfectly good and running FJ with all factory CA smog...and I do not want to ruin the overall value here. But looking for anyone who was in the same boat at some point. Saw this similar post here from long ago.

Can you desmog and keep all the rare OEM parts in a box - to be installed again later if needed? Is anything permanent when you desmog? I have seen the amazing write-ups here on how to do this procedure, but looking for general advice around the "why" do it and "will" it ruin your FJ value.

TIA :cheers:
 

Downey

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Your first issue is you are bringing up the subject of "de-smogging" on the forum that has evolved into the "restoration" forum, no longer a good site for guys who peddle "aftermarket" pieces. Next, a lot of the post you are about to receive involve the question; "how do you intend to use the vehicle"??. Seems the popular choices are "pristine show room restore" or "use and enjoy the hell out if it". For this latter group de-smogging is only half the process, the second half is installing upgraded ignition, headers, and fuel injection- - -then enjoy the hell out of it.
 
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Your first issue is you are bringing up the subject of "de-smogging" on the forum that has evolved into the "restoration" forum, no longer a good site for guys who peddle "aftermarket" pieces....
Huh? Not following you at all here....never saw Mud as a restoration-type forum. And why does that matter for my question? Just trying to follow your logic/opinion.
 
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I say leave well enough alone for now. Think about why you bought it in the first place and what your plans for it were. If you're thinking about changing paths, form your plan and then follow it through. If that involves removing parts store them till you're sure you won't be going back. You can also sell them as people are always looking for stock parts. Why go through a bunch of headaches you don't have to.
 
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Desmogged my (non-CA) '76 and installed a Sniper - everything is reversible if one ever wanted to go back to full-stock for either legal or restoration purposes, provided you bag and tag things and box all the bits up.

I do like my Sniper setup, but whether you'd see gains from desmogging that are worth the time, that depends on your rig.
 
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I say leave well enough alone for now. Think about why you bought it in the first place and what your plans for it were. If you're thinking about changing paths, form your plan and then follow it through. If that involves removing parts store them till you're sure you won't be going back. You can also sell them as people are always looking for stock parts. Why go through a bunch of headaches you don't have to.
Great advice there @B y r o n !
 
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Desmogged my (non-CA) '76 and installed a Sniper - everything is reversible if one ever wanted to go back to full-stock for either legal or restoration purposes, provided you bag and tag things and box all the bits up.

I do like my Sniper setup, but whether you'd see gains from desmogging that are worth the time, that depends on your rig.
Subscribed to your YouTube channel :)
 

izzyandsue

Izzy
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Only a problem in Cali as far as I know. Here in the south, you can remove all the extra pieces and it should be fine. Follow up with the GA club or Upstate SC club, plenty of desmoged ones there.
 

thorslc1977

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I would leave it the way it is. How much performance are going to gain? Who knows what the future will hold? I know out west here states like Colorado and Arizona are moving towards more stringent emission controls. Who is to say that trend won't continue into other states? At least document and save very carefully every part. I have a Federal 77 model and keeping it all original has saved me many headaches here in California.
 

Downey

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Huh? Not following you at all here....never saw Mud as a restoration-type forum. And why does that matter for my question? Just trying to follow your logic/opinion.
Keep reading all these posts, I think you might start to understand my opinion, they seem to support what I wrote ???
 
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I don't have to worry about this because mine is a 1970, but IMO the reason to do it is simplicity. Less potential sources of vacuum leaks for components that may no longer work and a cleaner engine bay. Many of these add ons were afterthoughts meant to make an older engine comply with newer standards and were not part of the original engine design (licensed from Chevy way back when.) For example dig into ported vacuum advance vs manifold vac advance on timing and the respective impact burning hotter to clear gasses can have on the valves. My guess would be that a desmogged 2F with a Sniper would run cleaner than an original smogged version at a tailpipe test anyway.
 
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micruz60

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. My guess would be that a desmogged 2F with a Sniper would run cleaner than an original smogged version at a tailpipe test anyway.
This is a real worthy reason; I would love to see it proven.
 
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Does depend on how long you plan on keeping the rig - but it's easy enough to put back on in the future for resale if you're keeping it for a while.

I also wonder on the Sniper vs original, but we don't have checks here so I have no clue what the rig does now with the ECU controlled fuel and spark. I still had the factory-new results though from pre-delivery checks - that would at least tell what an OEM setup did in "as new" condition for an early '76 (9/75). I can't tell what the actual value is for CO - 14% seems high, but who knows. Found the specs for Colorado's testing, and they'd look for 2% and under 600...maybe it's .4%? 🤔

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Seems the popular choices are "pristine show room restore" or "use and enjoy the hell out if it".

I think you would find most are of neither of those. Lot room between a garage queen the owner usesq a California duster on it just parked in the garage and those who don't feel they gone four wheeling unless that added new dents or break something. Considering what people are paying for clean FJ40s today it's a honest concern if your hurting the value of your investment. My opinion if you aren't willing to use it off road with the risk of pinstriping the paint leave it stock and getting running as best you can with emissions on. Few years ago I know of a case someone was looking for emissions parts for a 60.series. Person had no intent of installing emissions but rather he wanted them for if he sold it could include a box of emissions parts. If he had everything who knows. Personally emissions would need to be in place and a good emissions test before I would consider a vehicle stock. If a seller said everything is and would be easy to put back on would say then why haven't you done it. Mid seventies on 40 series emissions are a nightmare. I would put no value on a box of parts.
 

Pighead

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I am a fan of the desmog. Bought my '74 Pig in 1986. Quickly assembled parts for a desmog. Swapped parts every two years for the test. PITA.
Got the all-clear from DMV c.2000. Did a happy dance. Did an engine rebuild soon after with a bore, balance, RV cam and stuff. Runs SO much better. Easier to diagnose, no VSVs or BVSVs or anything. I got one vacuum line. Easier to wrench on, that air rail was in the way of everything. Runs cooler, stronger, better.
Big plus, the F engines are a thing of beauty. A joy to behold. The nekkider the better. I hated the smog stuff, i love my stripped down F/2F mixmatch.

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