Do they even make a l20b carburetor rebuild kit?

[datzenmike]

S10? I would guess a 2.5 liter engine? What was the 340 Hitachi from? Does it have a threaded post in the center of the carburetor that holds the air filter on???

[Marv]

21 hours ago, ]2eDeYe said:

Maybe a clogged cat? 

I did open two 3/8" holes before the cat- as I had that drill bit available.  Not sure if I should finish cutting it up. But I am running out of ideas. Thank you everyone for all the posts. 

[Marv]

21 hours ago, datzenmike said:

S10? I would guess a 2.5 liter engine? What was the 340 Hitachi from? Does it have a threaded post in the center of the carburetor that holds the air filter on???

It is the S10. 1.9l engine, I researched it and it is all original, they came with the isuzu engine. It does have the threaded rod that holds the air cleaner cover with the one butterfly nut, and three hasps at 120 degrees

[datzenmike]

On 10/1/2019 at 4:59 PM, Marv said:

.......but if I try to drive, it feels like I want to take off in 4th gear..... It starts perfect, acceleration pump squirts nicely strong. But when in gear, it bogs down-

 

If you can drive it. at all take it out for half an hour then pull over safely and remove a spark plug. Don't let it idle though. From your description it sounds lean. A badly lean engine will severely lack power and the plugs will run very hot and self clean till the porcelain insulator is white. Normal is a light tan or brown. See what you get. 

[Marv]

Alright, the truck runs like a champ if I move the choke to almost close, like 6mm closest to being fully closed. 

    But now the issue is if I stop, then I have to manually move the choke to fully vertical, so starts perfect (hot)- in the morning I would have to move it again to make sure it closes. 

     Would it be wise to replace the automatic choke? It is that black cover housing. I notice it is missing a piece of brown plastic, not sure if it is bakelite- any thoughts?

  And yes it is running lean as it does misfire when coasting, but rich on first start. Thank you all. 

[datzenmike]

The choke flap is hooked over the choke coil inside that round black plastic thing. Behind the coil is an electric heater that warms it at a set rate. As the coil unwinds for the heat the choke flap opens.

 

The choke needs a switched 12v supply to power the choke heater.

[Marv]

The choke is working the way is supposed to work- But I have to manually move it to keep it 3/4 closed when warm, as I have too much air still coming in (I guess)- so not sure what else to check, I sprayed carb cleaner, replaced all vacuum hoses, and checked egr, and the rest of the funky pieces added, including the air pump. 

    For now I guess it runs perfectly fine, no hiccups, but of I did not move the choke, it would be too lean. Anything else? Could it need another cleaning? Thank you all.

[Clint760]

You Can usually loosen the bolts on the electric choke and try adjusting it by turning it a little bit .

[datzenmike]

Usually. Then the emissions police made a design change and riveted the heater on. Because they felt that owners would only screw with the setting and run it too rich.

 

 

 

The casting has a protrusion that fits the black plastic cover preventing it from being twister lean or rich. I used an angle grinder to remove the bump and make it adjustable.

[Clint760]

Thank you in advance . I think I am running a little rich. I like having a additional adjustment option.  I am going to do this to mine .

[datzenmike]

Well, rich when the engine is started up cold but it quickly becomes leaner and within 5-8 minutes the choke is thoroughly warmed up and is turned off. Winters coming and colder weather. The colder it gets the richer your choke sets itself... all automatically but I find with most carburetor engines you need to make a fine adjustment towards richer. Now I don't think it's actually richer, after all once the choke flap is closed, turning the adjustment more rich certainly can't close it further, but it does take longer to warm up and turn off. There's nothing more annoying than driving several minutes with the heat gauge not even moving yet and when you pull to a stop the choke is almost off and the engine is struggling to idle because it's cold.

[Clint760]

That makes since it does smoke white so hopefully it's just water in the tank or running a little rich. but I plan on rebuilding the engine .

[datzenmike]

Rich on fuel will produce black smoke. Usually the carburetor is jetted properly unless an unknown carburetor is put on. Over rich is from having the choke on but should open as the engine warms up. Take the top of the air filter off after warm up and look. Is the choke still closed? or open?

 

Water doesn't mix with gas in an amount that would steam up the exhaust. The engine won't run on water. It's totally normal for exhaust to show white when it gets colder. If you smell it and it has a sweet anti freeze smell it may be coolant but this is unlikely.

[Marv]

Hello gentlemen,

   Last night I was looking to see of I found a PCV valve (1.9 engine does not have it) I am not sure what T they were trying to sell me.

   Anyhow I tested the choke pull off vacuum, and it does not hold, like the diaphragm has a tiny hole. Would this cause an issue after the car is warm as well? It is a pain to even remove it. Any info would be appreciated. 

[datzenmike]

The choke unloader? Has a small loop of hose to it? It may have a built in bleed.

 

I think under heavy throttle the vacuum pulls the choke off so you can get maximum power. When the engine is warmed up this isn't going to do anything.

[Marv]

On 10/15/2019 at 10:04 PM, datzenmike said:

The choke unloader? Has a small loop of hose to it? It may have a built in bleed.

 

I think under heavy throttle the vacuum pulls the choke off so you can get maximum power. When the engine is warmed up this isn't going to do anything.

Thank you. 

[Pacific coast Datsun]

Remove the Hitachi carb & insert it into the closest trash receptacle..go to www.piercemanifolds.com & purchase a Weber 32/36 carb & adapter plate..install & adjust the idle & air fuel screws..enjoy driving your truck..total cost is approx. $250 & will last the life of your truck.

[DanielC]

Do not like your stock Hitachi Carb?

I will take it.

[Pacific coast Datsun]

On 10/22/2019 at 1:29 PM, Pacific coast Datsun said:

Remove the Hitachi carb & insert it into the closest trash receptacle..go to www.piercemanifolds.com & purchase a Weber 32/36 carb & adapter plate..install & adjust the idle & air fuel screws..enjoy driving your truck..total cost is approx. $250 & will last the life of your truck.

No word back...are you still fumbling with the Hitachi or have you come into the 21st century & upgraded to a Weber ?