Will a partial De-Smog cause more problems, does De-Smog work increase heat in the Catalytic Converter? (1 Viewer)

[Carp888]

Hey guys, Newbie here, I've learned a lot lurking this site over the last few weeks, the biggest thing I've learned is how little I know, thanks for that. Here's my rig:

This Cruiser has been putting around ranches in South Texas for the last 15 years. The Smog Pump locked up recently and I am replacing it with an eliminator pully. I'm also replacing the China aftermarket carburetor with an after market Fuji.

Off and on for a couple of years now I have been experiencing what I call "won't hold an idle", it runs strong but dies immediately when you take your foot off the peddle. This problem comes and goes. The current plan to address this is the carburetor, clean out the EGR, replace the 3 port Vac Gas Filter (all ports are broken), and hook up/plug vac ports (most of which are disconnected).

I'm not out to do a full Desmog, I just want my rig to start every time and putt around a ranch reliably. But eliminating the Smog Pump feels like I have started down that road, and I question if I don't do a complete job then I'm going to continue to have vacuum/emission system issues down the road (if not worse).

So here's my question(s):

1. Half-Ass De-Smog - If I only eliminate the Smog Pump and do the things above will that likely lead to more/extended problems (because I did it Half-Ass)?

2. De-Smog Lite - I found a "Full De-Smog Kit" available: Toyota 2F Engine De-Smog Kit for 1980-1987 Toyota Land Cruisers - Landcruiser Parts - https://manafrelv.com/product/de-smog-kit-for-fj40-fj45-fj60-toyota-2f-engines-sku-2fdskit/ but I'd call that kit a "De-Smog Lite" compared to the Full De-Smog described in the "My Desmog Thread", including the set of instructions provided by @Borick attached below. (Thanks for doing that @Borick).

Would this "De-Smog Lite" Kit be ok to do without the rest of the Full De-Smog, or am I setting myself up for problems without finishing the job fully?

Last thing, I drive through a lot of tall grass, like half way up the radiator tall grass, and it gets compacted above the skid plate. Sometimes the catalytic converter will catch the grass on fire (I keep multiple extinguishers in the rig). @Borick's manual says "Without the AIR system, the cat should not get hot enough to melt down". The "should" in that statement makes me nervous. So would a Half Ass De-Smog or De-Smog Lite be less likely to increase temperature in the Catalytic Converter (as compared to a Full De-smog)?

Sorry for the long question, I mostly need to know what level of De-Smog I need to do for this hunting vehicle, we'll figure out the stalling issue. Thanks!

Some more pics of The Buggy:

 

[CruiserTrash]

All I have to add here is: what a cool truck.

 

[OSS]

Since your catalytic converter is not required where you are and it’s a life threatening hazard due to starting fires in tall grass — get rid of it.

The cat gets incredibly hot when the engine is running and if it’s not starting fires in the grass, it’s definitely cooking your manifold gaskets. The heat travels up the exhaust pipe.

GET RID OF IT.

Install a straight pipe.

Once you do that you’ll discover that the engine runs much better without all the back pressure form the cat.



Removing the smog equipment is mostly done to clean up the engine bay. Stuff is a lot easier to get to once all that smog stuff is removed. You won’t really notice any improvement in engine performance (except for removing the cat) and some of the smog equipment is best to keep. It’s not all evil.

 

[Carp888]

Since your catalytic converter is not required where you are and it’s a life threatening hazard due to starting fires in tall grass — get rid of it.

The cat gets incredibly hot when the engine is running and if it’s not starting fires in the grass, it’s definitely cooking your manifold gaskets. The heat travels up the exhaust pipe.

GET RID OF IT.

Install a straight pipe.

Once you do that you’ll discover that the engine runs much better without all the back pressure form the cat.



Removing the smog equipment is mostly done to clean up the engine bay. Stuff is a lot easier to get to once all that smog stuff is removed. You won’t really notice any improvement in engine performance (except for removing the cat) and some of the smog equipment is best to keep. It’s not all evil.

That last sentence in your reply has taken away a lot if my anxiety, thank you.

So you think my plan to replace the frozen smog pump with a pulley (and not do any other de-smogging) is fine for my purposes?

No Cat would be awesome! The problem there is that we drive around and hunt directly out of this rig. Quieter is better and very loud is bad. If there is some giant super-muffler that would keep the noise down closer to stock I'd be way down with removing the Cat. But you're right, I need to get rid of the Cat.

Thanks

 

[OSS]

Yes -
A smog pump replaced with a idler pulley is fine. That’s what I did.
And the exhaust is not significantly louder with the cat gone. It sounds a little different (better) but definitely not a problem. Not annoying, not loud. It actually sounds a lot better without the cat. You’ll like how it sounds. And the engine runs much smoother above 2000 RPMs without it. The cat strangles it.

 

[Carp888]

Yes -
A smog pump replaced with a idler pulley is fine. That’s what I did.
And the exhaust is not significantly louder with the cat gone. It sounds a little different (better) but definitely not a problem. Not annoying, not loud. It actually sounds a lot better without the cat. You’ll like how it sounds. And the engine runs much smoother above 2000 RPMs without it. The cat strangles it.

Sweet! I thought the noise would be awful. I would have done it a long time ago had I known it wouldn't be.

Thanks!

 

[Spook50]

Since your catalytic converter is not required where you are and it’s a life threatening hazard due to starting fires in tall grass — get rid of it.

The cat gets incredibly hot when the engine is running and if it’s not starting fires in the grass, it’s definitely cooking your manifold gaskets. The heat travels up the exhaust pipe.

GET RID OF IT.

Install a straight pipe.

Once you do that you’ll discover that the engine runs much better without all the back pressure form the cat.



Removing the smog equipment is mostly done to clean up the engine bay. Stuff is a lot easier to get to once all that smog stuff is removed. You won’t really notice any improvement in engine performance (except for removing the cat) and some of the smog equipment is best to keep. It’s not all evil.

Beat me to it. Safety (of many) versus legality, and in this case legality is a moot point.

Another vote to lose the cat, ASAP.

 

[chubot]

I’m thinking of doing a half ass desmog myself. I see the hoses and vacuum valve attached to the smog pump and a hose going to the air cleaner And the air injector rail. But there’s an oil cooler looking thing on the exhaust side of the block that has a pipe coming from the exhaust manifold and a flexible pipe coming out the other side and going to the carburetor. Does anyone know what it is and should I remove it as well.