More 78 FJ40 California smog woes…

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Passed!

Charlie’s jet (1.24 CA spec) was lost in the mail. JB supplied a collection of 3, one (Kyster?) of which was close but I tried to drill out with mixed results - snapped a carbide drill, only one I had close to the right size, etc. Then I remembered the online parts list with all the discontinued jets had shown only one jet (21253 - JET, 2ND MAIN Replaced by: 90999-4113 ID=1.38 HIGH ALTITUDE) available. Looked it up and saw the ID=1.38 (.054331 inch) and realized that’s only around a .001 (inch) larger than the stock Federal 1.36 (.053543 inch) Main jet. Called Toyota and my buddy there said they showed only ONE at the warehouse - he got it for me the next morning (AM, today).


Changed the oil. Managed to pull/replace (see below) the main jet without removing the carburetor. Warmed it up and tried to adjust what I thought would be lean (still don’t really know what I’m doing) and finally set a raised idle to around 800 rpm. Amazingly, it passed - see numbers below.


Changing the jet on the engine (from my perspective) requires a screwdriver filed to perfect fit. A gentle shot of compressed air in one jet access hole seems to pop a loose/lost jet right out the other access hole.

smog_pass.webp
 
antFJ said:
How's it run after the modifications?
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Seems to still run well, I’ll lower the idle back around or a little above the 650 rpm. Now that I’ve got a good Toyota jet installed that’s just a bit richer than stock (Federal) and still passes smog I’ll keep that and play with tweaking everything else for a while. To be truthful I think the 1.50 jet was a bit too rich. Not sure how it all works with present-day bad gas, etc. etc. Never checked the plugs but the pipe showed a little black stuff and sometimes the engine would/could start with no choke, etc. In general the more I drive the truck, the better it seems to run (knock wood).
 
ColonelMustardFJ40 said:
I have used a split blade screw driver to easily remove and replace these jets without disassembling the carb.
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I had a small one once... need to get a few more. Great for starting and removing but I still think a good fit is even more important to keep from messing up the jet on torquing in and out.
 
winnie said:
congrats, but geez, what a pita ... and what does it all solve from an emissions point of view ... :bang:
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Well, the numbers pretty much show what it solves from an emissions point of view. AND, now it's WAY below the "gross polluter" level now.

:meh:
 
surfpig said:
Well, the numbers pretty much show what it solves from an emissions point of view. AND, now it's WAY below the "gross polluter" level now.

:meh:
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agreed, from a micro, individual truck point of view, the numbers speak for themselves ... from a macro policy point of view unless all jurisdictions (including here) are on the same page I'm not sure, but that's clearly a discussion for another day ...
 
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