First carb rebuild...hard earned success

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HOW'S THIS IDEA SOUND?!?

If I have a donor, and IF it's really only the Accel Plunger Pump that's gone bad.... Could I minimize the work and just swap in the donor's air horn?

Not ideal, but if it can keep me running until a full rebuild kit shows up it might be worth it. Other than being careful with the gasket, anyone foresee a major problem with that plan?
 
FJ Noob said:
HOW'S THIS IDEA SOUND?!?

If I have a donor, and IF it's really only the Accel Plunger Pump that's gone bad.... Could I minimize the work and just swap in the donor's air horn?

Not ideal, but if it can keep me running until a full rebuild kit shows up it might be worth it. Other than being careful with the gasket, anyone foresee a major problem with that plan?
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Pump isn’t part of the air horn. It’s below. It’s easy to replace. You don’t have to swap carbs.
 
Well, I would add, though it's not difficult to remove the Air Horn, if you're not familiar with these carbs, there are a LOT of little bits that can go 'BOING' and disappear into the same place those missing socks go ... You wanna hunt for small springs or tiny balls in the engine bay, have at it. You'll curse your first born if they disappear down the throat of the carb..... Much safer to remove carb and do on the bench. Plus, keeping the linkage straight is difficult. Good if you have a spare carb to compare.

As stated, highly recommend a MUD Carb guru, either Mark A www.marksoffroad.net in Burbank, CA or Jim C www.tlcperformance.com in OH.

But as NGUY says, there are others, I just have no experience with them. I like to give the business to vendors who contribute to this board.
 
NeverGiveUpYota said:
Pump isn’t part of the air horn. It’s below. It’s easy to replace. You don’t have to swap carbs.
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Ok, you gotta walk me in on this one.... Multiple people have said it can be done without swapping or removing the carb, but HOW?

I'm looking at/talking about page 6-4 (Fuel System), Fig 6-8, item No. 1 in the August 1980 2F Engine Repair manual. Also shown as item No. 2 (Pump Plunger) in Fig 6-10.

Am I completely missing what part you guys are talking about?

I figured swapping the whole air horn would prevent me pulling individual parts and potentially busting more rubber boots.

****EDIT: @Spike Strip great point about all the little springy parts. I would've learned that the hard way and gone from re-building a carb to looking for diesel by the end of the day!!!

Rebuilt kit and 2ndary Diaphram ordered, but won't be here tomorrow. Looking for a down and dirty solution to keep me going until the mail shows up.
 
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FJ Noob said:
Ok, you gotta walk me in on this one.... Multiple people have said it can be done without swapping or removing the carb, but HOW?

I'm looking at/talking about page 6-4 (Fuel System), Fig 6-8, item No. 1 in the August 1980 2F Engine Repair manual. Also shown as item No. 2 (Pump Plunger) in Fig 6-10.

Am I completely missing what part you guys are talking about?

I figured swapping the whole air horn would prevent me pulling individual parts and potentially busting more rubber boots.

****EDIT: @Spike Strip great point about all the little springy parts. I would've learned that the hard way and gone from re-building a carb to looking for diesel by the end of the day!!!

Rebuilt kit and 2ndary Diaphram ordered, but won't be here tomorrow. Looking for a down and dirty solution to keep me going until the mail shows up.
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6 or so screws hold the horn on. One bolt holds the acc plunger to the side of the horn. The linkage has a little finger that juts into the plunger stem. Once that bolt is removed the linkage finger can be pulled out of the plunger stem then it will lay down ward out of the way. Undo the 6 or so vertical screws on the horn and lift it off. The plunger stays behind. It’s acordian boot will require being pressed down through the horn before it can be fully lifted off. Then simply pull the plunger out. As Spike said, there’s a small spring under the plunger but it won’t just jump out at you, it’ll stay in the base. Soak the new plunger in 90wt for 2-4 hours. Install it then slide a new boot up into the underside of the horn then slide it down w/ the horn onto the plunger stem. Yada yada.... basically that from memory.
 
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But I get the impression this is anxiety producing just talking about it... pull the whole carb... oh my, don’t lose any of the teeny tiny clips... and send it off for an easy $250+ weeks on end rebuild.
 
NeverGiveUpYota said:
6 or so screws hold the horn on. One bolt holds the acc plunger to the side of the horn. The linkage has a little finger that juts into the plunger stem. Once that bolt is removed the linkage finger can be pulled out of the plunger stem then it will lay down ward out of the way. Undo the 6 or so vertical screws on the horn and lift it off. The plunger stays behind. It’s acordian boot will require being pressed down through the horn before it can be fully lifted off. Then simply pull the plunger out. As Spike said, there’s a small spring under the plunger but it won’t just jump out at you, it’ll stay in the base. Soak the new plunger in 90wt for 2-4 hours. Install it then slide a new boot up into the underside of the horn then slide it down w/ the horn onto the plunger stem. Yada yada.... basically that from memory.
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Perfect...thank you. That's what I was putting together from looking at the FSM, but thought maybe you guys were talking about a different part.
 
NeverGiveUpYota said:
But I get the impression this is anxiety producing just talking about it... pull the whole carb... oh my, don’t lose any of the teeny tiny clips... and send it off for an easy $250+ weeks on end rebuild.
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No, just frustrating when people provide douche-nozzle (note above) and half-assed "nope, not it" responses to people that truly want to learn...yada yada yada generally from my outlook on life.
 
FJ Noob said:
No, just frustrating when people provide douche-nozzle (note above) and half-assed "nope, not it" responses to people that truly want to learn...yada yada yada generally from my outlook on life.
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We said it wasn’t hard. We meant it. But I do remember before I’d ever pulled my carb and the anxiety I had at doing it for the first time. I do believe I replaced my acc before pulling the actual carb too. If I can do this, you can to.
 
NeverGiveUpYota said:
We said it wasn’t hard. We meant it. But I do remember before I’d ever pulled my carb and the anxiety I had at doing it for the first time. I do believe I replaced my acc before pulling the actual carb too. If I can do this, you can to.
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I have an instruction book. I know I can do it. Any anxiety comes from the thought of having to drive the "break in case of emergency" Corolla on Monday.
 
Not directly LC related, but I found and replaced the bad ignition coil on the Corolla.
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Now the pressure is off to get the LC running by tonight. Carb rebuild kit is ordered, but I think I’ll see if the individual parts from my donor carb will work in the short term. I planned on stripping that engine down anyway to prep for pulling and overhauling it. Might as well start today I guess.
 
Old plunger and boot pulled. Off to try and reclaim another one.

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Spike Strip said:
I would also strongly suggest...
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Thanks for the “tip” :rofl:

Yeah, I stayed up late last night watching all of Pin Head’s videos and studying the diagrams in the FSM. I don’t completely understand the science behind every screw, passage, and linkage but I get it a lot better conceptually than I did 24 hours ago.

I’m only struggling a little bit with the main graphic showing the circuits. Mostly because of how it’s shown in 2D versus the actual relationship of the bowl and chambers. Probably make more sense as I pull the real one apart.

Normally, should fuel bypass the seal on the plunger? Doesn’t seem like it should because the boot isn’t completely sealed. All my leakage is due to bypassing the plunger seal and coming out the deteriorating boot. Obviously something to be addressed, but that doesn’t totally make sense to me as the cause for dying at idle.

During idle, where is fuel being pulled from and what pulls it...is there a specific vacuum line I should pay attention to?
 
There's prolly five guys in USA who fully understand where all those Aisan carb circuits go and what they do. I'm not one of them. You have to realize this carb was prolly the most-advanced and smog-compliant ever used before Toyota switched to Fuel Injection, in USA.

That 2D diagram you ref will become more clear once you've got one of these carbs apart. Even then, it took me a while squirting carb cleaner in one place and seeing where it shot out to 'kind of' understand what goes where, but of course that doesn't even scrape the theoretical aspect of what's the carb doing when you mash the throttle and vacuum approaches zero and then the Power Valve kicks in ....

You should get virtually no fuel past the Accel pump plunger. Yours is toast. Needs replaced.

At idle (when manifold vacuum is highest), fuel is pulled thru the Idle Circuit (the thing the Mixture Screw adjusts). It's another one of those small holes in the primary barrel.

This is an excellent thread:

forum.ih8mud.com

Aisin carburetor idle circuit routing

I am working to diagnose an idling issue on my trail rig and am fairly convinced that the idle circuit has a blockage somewhere. Can someone help explain to me the routing of the idle circuit from start to finish? Carb is a December 1969 production 2-barrel Aisin. Idle mixture screw will not...
forum.ih8mud.com forum.ih8mud.com
 
FishTacos said:
1999 Toyota Corolla - Fine AF : from "best of Craigslist.

I am also a proud Corolla driver. Still got a kick out of the above ad. Well worth the 3 minute read.
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This is funnie AF ! And true! Can't kill one of these bastids! Not bad for what is essentially a Toyota/GM combination of parts!
 
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