Life with a Chinese Carburetor (1 Viewer)

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Pin Head: This morning I felt really stupid. I didn't have dash lights or running lights but everything else worked. Several weeks ago when this problem first reared its head (I rarely drive at night) I jumped 12V into the wiring harness and had lights and figured it was the switch. Ordered a new one, it arrived last week, and no difference. So this morning I jump juice into the harness again, same results. So I checked the fuse panel, again, oops, there is a blown fuse, problem fixed.

So then I turned my attention to the electrical for the engine. New plugs, points, cap and rotor. Points at .008, put the distributor back in the hole, dwell checks 41*, idles smooth, once it starts. We went for a grocery store test drive. I have a good hill/entrance ramp. A car had come before me requiring me to stop before getting on the ramp so I'm in 1st instead of the normal 2nd. It pulls smoothly up the ramp and as I continue onto the highway, still climbing, shift into 2nd and it is smooth, no surging. It was fine around town, fine on the highway. But turn it off and it is back to the aggravating choke, pump gas, hope. It finally starts and pukes a black cloud and then settles into a nice steady idle. So essentially I am right back where I started ten days ago. The car should start with a touch of the key, that is when everything is right.

Sggoat: I agree. In this case I switched from an F engine to a 2F. While the guy did give me an Aisan carburetor, 2 bbl, it was not for this engine as it has the double ring/single ring venturis which ended in 1977 and the motor is 1983. Also the throttle shafts were rusty/frozen. I had already ordered this carburetor as the folks online seemed to be happy with it. Two years ago, knowing I was traveling to the USA for my daughters wedding, I bought an Aisan 2bbl on Ebay and had it shipped to Mark. It wasn't going to be ready in time for my return and I can't import a used or remanufactured part. I'm thinking I just have to bite the bullet and buy this Aisan that is available. I will look it over tomorrow. I did try the old Aisan that I soaked in gasoline and freed up and rebuilt with the kit. However, it has the same starting issue, but never had any surging. It is aggravating to say the least.

And did I mention that my rebuilt 3 spd transmission has started jumping out of 2nd & 3rd gear. Oh joy.
 
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Choke and pumping the gas pedal are the opposite of what you want to do on a hot restart as evidenced by the cloud of black smoke when it finally catches. It is much more likely to be flooded during a hot restart, so what you wan't to do is put the pedal to the metal and hold it without pumping. Then hit the key and let up when it starts.

The carb may be overheating when you shut it off and puking gas from the bowl vent tubes into the venturis.
 
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Thanks Pin Head. I have tried, today when we were parked underground at the grocery store, to not touch the gas pedal. Nothing. Pulled choke, still not touching gas pedal, started to hit but then didn't. One pump, no change, etc, etc. Just aggravating. In the mornings when it is cool, maybe low to middle fifties (about as cold as it ever gets down here) usually one pump and full choke and it will light off fairly quickly and then push the choke mostly in, not all the way, and it will high idle until warmed up. I usually leave the choke in that position as I drive the three miles to the bus stop where I drop off the wife. At that point I usually push the choke off but when I leave and go up the hill it just doesn't have anything. Frustrating because I know I enjoyed that two weeks of good function where it would start with the touch of the key, pulled strong, really made me happy with the new motor. But it was only that two weeks, at that one time.
 
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What you want to do is hold the throttle all the way open without pumping it. Then start it. If this helps, the carb is flooding after you start.

If it was mine, I would just disassemble it, clean everything out. Blow it out with compressed air and carb spray. Verify that all the tiny holes are clear by passing a nylon monofilament line through them and try again.

Here is the deal: It ran fine for two weeks. What could possibly happen to change that? Probably dirt and junk floating around in the carb left over from manufacturing and shipping ended up in the wrong place plugging something up.
 
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Pin Head I just logged on to reply to your earlier post. I had this thought that what is happening is the carb is not atomizing. So when pumped I'm dumping fuel into the intake manifold and it is being atomized in the combustion chamber until one cylinder lights off. That is why it blubbers to life and then blows out the raw fuel and once the engine is spinning faster than the starter can turn it the vacuum in the cylinders gets the atomization going in the carburetor and that is why it settles into a smooth idle. Which again points to the fuel plunger and "that" circuit, which is what I started chasing from day one. While I have not passed any filament through the holes I can certainly see that aerosol carb cleaner is spraying readily through those orifices (the pop up piston sitting on a spring over a check ball and below the fuel plunger/spring and check ball into the bowl. I have also verified that carb cleaner was blowing freely through all other ports from the mains up through everything you pointed out in the videos. Thanks for thinking about this with me.
 
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Why don't you just see if it restarts better with the throttle wide open and no pumping of the throttle? If so, the engine is flooded. This is a different problem than "surging", but I still don't understand what you mean by surging because I can't be there to see it for myself and you haven't described it in a way that means anything specific to me.
 
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Ah, by surging I am referring to the feeling in the pedal and seat of pants that the engine speed will change under steady throttle. Whether the throttle is floored up a hill or steady throttle on level road. With the old 1 bbl carburetor which had a very rich jet, a 1.50 I revised to a 1.08 and the surging was bad. So I increased to a 1.15 and it was better and at a 1.20 it was perfect. So with this carburetor the jets were not marked. I had swapped out the supplied jets with the high altitude jets stored in the bowl plugs before ever trying the carburetor. So my current configuration is with the kit jets which are 132 and 220 and I didn't notice any surging yesterday and will "feel" for it this morning as I will take the wife to work which puts me on the entrance ramp and the highway for a little bit.
 
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I would have bought the NOS Aisan by now....

I went through a similar experience a few years ago. I went through two chinese carbs-first one had leaks, second one ran fine for a couple of weeks until metal chips in the bowl started clogging up the orifices. I rebuilt my Aisan in half the time I wasted on these other carbs and it's been running perfectly for years. Starts on first crank every time.
 
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I was ready to go get it this morning. I had to stop for a half hour or so and determined that if the new Pin Head starting ritual didn't work, I was going to get it. Sure enough I just held the pedal to the floor, no choke, and it fired right up. So we'll see what happens over the next couple of days. I'm still thinking to buy the NOS Aisan just because it is there and it is a good price.
 
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Went back into town and bought the carburetor. The tally for today was 7 out of 8 starts required pedal to the floor and full choke. I have a lot of work to do around the house and two weeks of carburetor business has gotten in the way. So, as long as the carburetor is working I can live with it. But the next time I have to pull it off it gets a new Aisan. I enclosed a picture of the receipt so you wouldn't think I was funning you over the price. It shows $348.21 plus $41.79 IVA. Now that I'm 65 I get all my sales tax back:). Also you should be able to see that I went down to Casa de Cable (House of Cable) and he made me up a good choke cable that has the barrel on the end. The unit supplied on the Chinese carburetor fits into that hole but since it can move fore/aft as well as rotate it is a real joy to connect under the hood. The last picture is of the Aisan the fellow gave me with the motor that had frozen secondary throttle shaft. I will probably play with it some more. It ran okay, but didn't start good either. But on it you can see the type of choke cable connection used. Very easy since all it can do is rotate which is pretty easy to manipulate with the cable itself. However, with either one, once you tighten the screw you kink the cable making the next installation a bit more awkward, that is why I wanted a proper setup. Oh, that new cable cost me $14.

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I will try to help. When I bought my 40 about year and half ago I had a miserable time with carb issues. This is a de-smogged California flavor 2F. I tried everything. Sounds like you are having the same symptoms I had. My problem was having to start using the choke hot or cold. Hesitation or surge depending on how I screwed with jets and such. Idle was horrible. I replaced my intake/exhaust gaskets. Verified vacuum, verified dwell. I also removed the Asian carb and bought the Chinese carb. Ran no better. I played with jet sizes. Finally I found a used Asian carb on ebay for $200 that claimed it was professionally rebuilt. It was worse.

So, I had to educate myself. I took one of my now many carbs totally apart. I traced the idle circuit so I could understand that. Then I took the $200 Asian and rebuilt it with a new kit. I have rebuilt many a carb over the years, so I felt comfortable doing this one. I remember that the primary jet has 150 on it (for size 1.50 I think). Can't remember all the other jets.

I will try to make this short. I put this carb that I just rebuilt on and still the truck would not idle right and drove horrible. Here is what I have learned and I can tell you my truck now runs fantastic.

Idle circuit - If your idle circuit is malfunctioning (clogged, fuel cut solenoid malfunction), the only way the truck will idle is by you screwing in the fast idle screw, which forces gas to flow out the primary venturi (which is wrong operation). When the idle circuit is correct, you do not see fuel spitting out the venturi at idle. I have had two idle circuit failures in the last 1.5 years. #1 - trash in the hole in the main body that leads to the idle mixture screw. Had to remove the idle mix screw and blow it out with air. A piece of trash popped out and is probably why the carb was on ebay. I bet the owner couldn't find the problem. #2 Recently the Jet that gas from the bowl flows through feeding the idle circuit was clogged. Both times as I screwed around with the carb to make the truck idle, I would find that at idle gas was spitting out the venturi and low and behold I would find some problem to correct with the idle circuit. And then the truck would run wonderful.

Seems that once I resolve the idle circuit issues, all the other symptoms regarding starting and surging go away. I guess because before I understood how the carb should be reacting, I was adjusting the fast idle all wrong to get the truck to run and with that all wrong and the idle circuit not working, the carb just does not act right.

I suspect I could take that Chinese carb and go through it, find some issue with the idle circuit, fix that and the darn carb be OK. Just a theory, but so far I have experienced that the idle circuit working correctly is very critical to the operation of the carb as a whole.

Look down into the top of the carb with truck at idle. Do you see gas spitting out the venturi on the passenger side of the carb? If yes, find the problem with the idle circuit. Gas is coming up out the bowl, through a jet, up through a hole in the top of the carb, then through the fuel cut solenoid, then down a hole to a hole that leads down the main body to the idle mix screw. That path must be totally clear for correct idle. Hope this helps.
 
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Thank you for taking the time to thoroughly explain your situation. You are spot on in thinking that I am addressing the exact same issue. From day one with the new motor the mechanic pointed out that the fuel plunger was not working, wouldn't pump. It took two weeks getting other things sorted out after the new motor installation before I could address it, and that required the same starting ritual you refer to, hot or cold. I purchased an APCO, made in Japan kit, and only installed the fuel plunger itself. I blew carb cleaner through the idle circuit, only removed the top of the carburetor (entire carb off engine). It ran perfect for two weeks and then started the same thing over. Mind you, when they installed the new engine it got two new fuel filters. I change them at every oil change, 3,000 miles. The upper always looks good, the lower definitely needs replaced. Like you I am comfortable with rebuilding the carburetors. Unlike you, I no longer have access to Berryman Carb Cleaner or an air compressor. I had a pretty nice shop in Seattle. So I have been reduced to soaking in gasoline, per the FSM actually, and blowing out with carb cleaner, profusely. So with the fresh tune up and two days of service, three I guess including this mornings run to the bus stop, per the Pin Head recommendation I am putting it in neutral, pressing pedal to the metal, pull full choke and crank. Sometimes it is just a few revs and it lights off, other times it approaches the uncomfortably long cranking before lighting off. Then in the morning (49* today) the choke goes to slightly closed and it idles just fine. The throttle response is fine, there is no surging anymore. It is aggravating. So I am considering buying an air compressor, it is like $700 for a 4 hp, 30 liter tank with wheels and a handle for moving it around, not cheap. All of the other ones I have seen, including the tall units, are 2 hp or less and they can run $1,800!?! So at the moment I am living with this carburetor. But as I have said, when, not if, it comes off again I will install the new Aisan. I thought it curious that installing the kit jets at 150 and 220 (and you are correct, they should be interpreted as having a decimal after the first number as they represent 1.50mm and 2.20 mm diameters) it runs better. The old 1bbl gave me nasty looking plugs with a 1.50 and surged and was too lean with a 1.08. After installing 1.10, 1.15 the 1.20 worked out to be just perfect. So I would have thought the same applied to the 2 bbl, but without a number on the jets I have no idea what size they are. I used a toothpick stuck into the jet and a pencil mark at the bottom of the screw slot to "measure"/compare and clearly what I have installed are the largest I have on hand. Again, thank you for taking the time. Clearly an air compressor will push through the circuits better than aerosol pressure.
 
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A drill bit slid into the hole of the jet works as a measuring device (I have a very expansive drill bit collection). You can figure out what those POS jets that came in the Chinese carb really are. My Asian carb from Ebay came with a 160 main. I suspect someone screwed up which jet went where. I changed it to a 150 and improved my gas mileage. Specter shows an even smaller jet, but maybe that is with all the emission stuff, which is plugged on my rig.
Land Cruiser Carburetor Jet Size FAQ
FYI, that jet that meters the gas from the bowl up to the fuel cut solenoid is TINY. It doesn't take much in the way of trash to clog it. With the top off the carb, unscrew that jet that has the long tube (jet in the main body you see with the top off, jet on the pass side of carb with carb installed). See if that is clear. That puppy can cause a world of hurt to your mental state.
 
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Those jets, primary and secondary, are not numbered either so they got replaced with the kit units number 65 and 90. If it comes back off I will check it out. Trying to catch up on some overdue yard work, been messing with carburetors for two weeks.
 
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per the Pin Head recommendation I am putting it in neutral, pressing pedal to the metal, pull full choke and crank.

No. You don't use any choke on the hot restart/flooded engine starting procedure. The choke and pumping the pedal will make the rich mixture worse. Just hold the throttle wide open when cranking.

The hot restart problem is not likely to be related to your idle problems. Fuel is either boiling out of the bowl or it is slowly siphoning out through the idle circuit.
 
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As pin_head said and maybe I didn't note in my long winded text, with my carb functioning properly I rarely use the choke. I don't think I even use it in the morning when the engine is cold on warm days. I guess as it cools down I might need it.

When my carb was all screwed up and the idle circuit was putts I had to use the choke every time I started it. I am still somewhat of a novice with this model carb, but to me the choke closed must be forcing the carb to pull gas from where ever it can so it has fuel to start up.
 
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So that is bypassing the fuel plunger circuit?

toyota land cruiser 78 vendo o cambio - Cuenca

I will drive this vehicle over to my mechanic on Friday afternoon for his inspection. Sure wish I had done that with the 1970 Beast. I had been looking for a rig with say a bad motor, bad electrical, bad interior, instruments, etc. but a good body and transmission. Wishful thinking. I had a friend look at three in Quito for me, he wouldn't even drive them. They were of course in the lower price range, under $5K. This one I looked at several weeks ago and it would work for me, but the price is high. So now I am thinking to use this vehicle, take my good stuff off of my '70 and use on this one after getting it painted. While it says '78, the gas tank is under the body, which I like. It has a heater/defroster that needs water hoses and I see some funny electrical at the blower motor, but it does work. I don't care for the roll cage as it makes for two very short jump seats in a rig that doesn't have much room inside to begin with. It does have power disc brakes.

Any comments on what to look for are greatly appreciated.
 

AussieHJCruza

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X2 on rarely using the choke when it's all dialed in properly - on my FJ45 with the DUI dissy and Procarb carby, I never used the choke, even when she was cold. Cold start was 5 pumps of the throttle and about 2 revolutions of cranking, and hot start was throttle to the floor and about three revolutions of cranking.
 

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