A tale of two carbureutors

[Helomedic1171]

Here is a very concise procedure for the 2100 / 2150 carbs. I used this PDF, and my carb works great. Might have even gotten this from somewhere on this site!

yes, I got it and at least one other from this site, as well as jeep forum, offroad.com, and a few others. they were all very helpful during reassembly. This one you posted says 7/16", the other I downloaded says 9/16", and the rebuild kit instructions/data table say a variety of things, but for a Ford AMC 258 i6 / 4.2l , it says 3/16". I'm sure you can understand my confusion based on multiple sources, which is why I'm asking others what their experience is. I wanted to ask others since that was more than twice what the kit listed for most of the applications on the data table.

 

[Helomedic1171]

I'd follow the instructions that came with the kit, the kit knows what the kit needs. Essentially the float will be level in the bowl when it shuts the gas flow off.

The common theme I keep seeing g between all of the write ups and PDFs seems to be what you said. My measurements keep coming out to 1/2" and since that's right in between the 9/16" I saw in one file and the 7/16" that another one reports. Also, the float is pretty level when the needle occludes the seat with my finger. I'm gonna run it and see how it works.

The electric choke covers, the black plastic piece you're talking about, are universal between carbs, every parts store should have one in stock.

No dice as of yet, Autozone and O'Reilly's want $40, so I'm going to search around, maybe I can try the junkyard again, though this was the only carb on any of the Ford vehicles I saw last time. Otherwise, maybe I could try using the one off the BBD carb? It has one wire just like the Ford one does. I'll compare them tonight or tomorrow. Thanks for all the help so far, folks!

 

[elwood blues]

$40

Amazon for if you have prime. http://www.amazon.com/gp/product/B00029JK2S?keywords=45-258&qid=1450746619&ref_=sr_1_1&sr=8-1

Summit, $99 for free shipping Holley Replacement Choke Caps 45-258 - Free Shipping on Orders Over $99 at Summit Racing

 

[Helomedic1171]

$40

That's the face I made when they told me.

Prime is awesome, that's my next stop if the Carter one won't work. Dude told me the price and I figured I'd go searching after I got it mostly together. Funny thing, the one on the BBD looks identical to the Ford unit, except a single spade instead of a single bullet connection. I'll post photos once I get it put together.

 

[Helomedic1171]

And here it is is, all finished up! thanks for the tips and the help, you guys made my first carb rebuild go by really easily. Here are some photos:













By the way: what do I do with these three holes below the choke? or do I just leave them alone?





next thing I'm going to do is look for a few threads/diagrams and see how the vacuum routing works. here's what I have so far, though I haven't read much of it yet:

Vacuum Lines after Nutter Bypass - JeepForum.com

I'll post up questions after I read this one and a few others tomorrow and see what I can find.

 

[Woolyworm]

Looks good. IIRC, you need to close up one of the holes on the bottom of the carb - I forget why or which one but that does stick in my mind for some reason. Anyone else?


Wooly

 

[Fastatv]

The carb is looking nice! You can turn the choke to it's leanest position which will set the choke blade straight up...it won't come on.......until you find a good deal on the electric t-stat, but you won't have any choke, and it may be a bear to start this time of year. The holes in the choke housing may be blocked off and require nothing. Shoot some compressed air into each hole and see if the holes "dead end". The housing was designed to be used with the "stove pipe" heater as well ( instead of using and electric choke ) but if the electric choke was standard on the carb, those hose should be plugged from the factory. In regards to the vacuum lines:
- One port is a delayed port....for your distributor advance
- One port is live vacuum for the choke pull off
- Best guess is that any other small ports can be plugged
- Larger port (s) would be for PCV or possibly power brakes.
This is all from memory so best not take my word for it....

 

[IOPort51]

Looks good. IIRC, you need to close up one of the holes on the bottom of the carb - I forget why or which one but that does stick in my mind for some reason. Anyone else?


Wooly

It does take an adapter, I am sure you are aware. and the base gaskets are a chalange to seal.

Did you remove the throttle plates? I did and found that mose recomend that you not remove them. If you did remove them, be extra sure you got them re centered in the bore. If they are not you will never get your idle mixture right.

 

[Helomedic1171]

The carb is looking nice! You can turn the choke to it's leanest position which will set the choke blade straight up...it won't come on.......until you find a good deal on the electric t-stat, but you won't have any choke, and it may be a bear to start this time of year. The holes in the choke housing may be blocked off and require nothing. Shoot some compressed air into each hole and see if the holes "dead end". The housing was designed to be used with the "stove pipe" heater as well ( instead of using and electric choke ) but if the electric choke was standard on the carb, those hose should be plugged from the factory. In regards to the vacuum lines:
- One port is a delayed port....for your distributor advance
- One port is live vacuum for the choke pull off
- Best guess is that any other small ports can be plugged
- Larger port (s) would be for PCV or possibly power brakes.
This is all from memory so best not take my word for it....

Thanks! I'll test the holes out when I get back to the house. I'm going to try the electric choke and see if it works, if not, I'll do what you suggested. It's still waffling between hot and cool here in Savannah, so I'm probably OK until mid to late January without a choke. The child pull off is booked into the same vac port it was hooked to when I found the carb, and it seems to match the pictures I've found up to now, so hopefully that's correct. I know one of the big ones is bowl vent (the one near the data plate) so I assume the other big one down lower is for PCV. Worth a shot, right? There's a small one that come out the bottom of the air horn, I've read it's for filtered air, but not for what it does. I'll probably plug it for now. There's also the vertical one directly below the bowl vent tube, and the hook up for the power valve below that. I think I have any idea where they go, but let me know if anyone knows different -

Bowl vent goes to valve cover grommet without PCV

Big one on the base plate goes to PCV, this causes crankcase to vent and allows bowl vent to be sucked into engine

Power valve gets manifold vacuum source

One of the little ones, probably near the big one in the base plate, gets distributor advance

Little one under air cleaner gets capped

Other little one near mixture screws and accelerator pump gets capped.

Vertical port under bowl vent is still a mystery.

That's what I think I need, still a more reading to do.

It does take an adapter, I am sure you are aware. and the base gaskets are a chalange to seal.

Did you remove the throttle plates? I did and found that mose recomend that you not remove them. If you did remove them, be extra sure you got them re centered in the bore. If they are not you will never get your idle mixture right.

Thanks for the heads up - I didn't remove mine. I had a friend rebuild a carb for me once, he broke the screws off the choke plate into the rod. Since I did this one, I cleaned up around the plates and left them on. I did make sure they were kept open while soaking, though. The other carb I have which is really tough, I think the screws are rust welded to the rod, so they aren't coming off. I still have it soaking to hopefully loosen the linkage. Right now it's frozen, but maybe I can rehab it. If not, it's got some good parts I've already cleaned up and saved.

Oh, and I did get the adapter, and the nice thick isolator gasket for under the carb. I'll pay attention when I'm bolting it all together.

More to follow...

 

[elwood blues]

Is this what you're looking for?

The ports below the choke, yes, one needs plugged, the other one is for a tube, a copper tube, that from the factory went to the exhaust manifold. Basically the copper tube transfers heat from the exhaust manifold to the carburetor through the tube to heat up the coil inside the choke to turn it off.

 

[elwood blues]

I almost forgot; looking good man

 

[Woolyworm]

Elwood - I think the choke heat chimney actually comes up off the intake manifold - at least on a V8. Not sure on the 6 though.


Wooly

 

[Helomedic1171]

Is this what you're looking for?

Sort of - I found that one, and it's immensely helpful. What I need to find out is what vacuum source hooks to the power valve, and what vacuum source hooks to the vertical port on the front of the carb just to the left of the accelerator pump, below the bowl vent. you can see it here:



those are the last two ports I need to fit and I'm good to go. I finished the nutter bypass tonight, just need to thin out some wiring. as far as the rest of the vacuum, I'm following the same diagram you posted.

I almost forgot; looking good man

Thanks! I learned a lot, and it was really cool. You guys have been a huge help.

 

[Helomedic1171]

I think I found something...

gonna try it, seems like it might work. just need to find a good manifold source. would the CTO work for this? I'm not running the EGR, just the evap can.

 

[elwood blues]

Elwood - I think the choke heat chimney actually comes up off the intake manifold - at least on a V8. Not sure on the 6 though.
Wooly

You may be right Wooly, I honestly don't know about V8's. On the 1980 and older L6 AMC 258 i6 / 4.2l /AMC 232 i6 /199 exhaust manifolds, they had a copper tube that ran between the runners, and that's what it was for.




But, Helo's got an '85 and that style exhaust manifold doesn't have one.

I wouldn't use the CTO, there's not a lot of vacuum (volume of suction) there. Possibly use a "T" and split the EGR vacuum?

 

[Woolyworm]

Ahh, I see.

Helo - I mentioned sealing up one of the holes on the bottom of the carb but I searched around s but and I think you only need to do that if you are going with a manual choke.

Based on my research and memory so take with a grain of salt;

There are 3 types of choke assembly's.

1 operates with a bimetallic spring that contracts or expands using heat from the intake manifold chimney or the exhaust chimney as Elwood points out. As it does this it closes or opens the choke plates. There is often a small diaphragm that will force the plates to stay open a bit. Rotate the choke to adjust.

2 operates with a bimetallic spring that contracts or expands using heat generated from electric current (probably why the later models don't have a chimney). Rotate the choke to adjust. 2 will work in place of 1.

3 manual choke that operates with a cable - my preference because I could never get the others to work well for me and would need to adjust from summer to winter to even get close. And it was about $10. 3 will work in place of 1 or 2.

Cheers


Wooly

 

[Helomedic1171]

what about this one? (see arrow) it's capped on my Jeep for some reason, and it's definitely a manifold source.



(nevermind the fact that the photo has some craziness about the distributor being hooked to it, this photo isn't mine.)

 

[Woolyworm]

Also -

http://www.fourwheeler.com/how-to/e...ning-the-motorcraft-2100/#.VnrBQBNSIYw.mailto


Wooly

 

[Helomedic1171]

that was a cool article. I'm not wheeling the 85, just some dirt roads and mountain roads, but that was really cool info.

 

[Helomedic1171]

Ahh, I see.

Helo - I mentioned sealing up one of the holes on the bottom of the carb but I searched around s but and I think you only need to do that if you are going with a manual choke.
...

Cheers


Wooly

Sweet! Manual is my plan B. I've never had an electric choke, so I was going to try it. But if it doesn't work, off it goes.

Besides setting choke/idle settings, all that's left it to fab up a linkage and then it's ready to bolt on. This is getting exciting.