Carb Replacement Advice for '79 CJ-5

[Hedgehog]

My understanding is the difference between the 2100 and the 2150 was the altitude compensation device. But I could be wrong....

I have several with the Chilton being the very worst of the bunch. The Haynes was far better. Why? The Chilton had to many sentences like ....... To start work on the carburetor, first remove the carburetor ........ After reading a sentence like that I always went, "Whaaaaaaa, exactly how do I remove the carburetor? ......." That wasn't an exact sentence, but an illustration. The Haynes was far more complete. But to really get the straight scoop you need a shop manual. Unfortunately I don't have a shop manual for the '75, but I do have one for a '80 which has covered my 360 needs. A good manual, I mean a really good manual is a great, no it's a must have.

 

[IOPort51]

you should have a Chilton, a Haynes, a factory service manual. the laminated 11x17" color coded wire schematic and anything else you can find with your year that says "Jeep" on the cover. The go-to book is the FSM.

there is enough information on line about the 2100/2150 MC that you can read it every night for a week and not find it all. The MC carb is a snap to rebuild and even if you have money to throw at it I think the pride that you feel when you say " and then I rebuilt the carb". And as a plus you may even understand how the silly thing works. If I remember I will post a few pages when I get home and have access to my book marks.

One of the reasons they are difficult to find is that they are popular with the out law dirt track cars.

 

[gadawg31]

IO, I do have the 11x17 wire schematic and it was great when I was putting stuff back together. I have a Haynes manual, but it does not show the actual ports on the carb for placing the lines back on, too general. I think the service manual is going to help me get these lines on and ports plugged, that need plugging. Thanks again.

JD

 

[IOPort51]

Carburetor number Identification and Links Page

http://c805745.r45.cf2.rackcdn.com/motorcraft_2100_4100_manual.pdf

http://street2mud.com/webfiles/MC-2100 set up for a 258.pdf

Motorcraft 2100 2 Barrel Carburetor - B7A

the last one is a place to buy a "core".

 

[IOPort51]

IO, I do have the 11x17 wire schematic and it was great when I was putting stuff back together. I have a Haynes manual, but it does not show the actual ports on the carb for placing the lines back on, too general. I think the service manual is going to help me get these lines on and ports plugged, that need plugging. Thanks again.

JD

You are looking at this backwards. there are only two holes on the carb the ported vacuum and the manifold vacuum. these control things , The distributor advance, the emissions system, the thermostatic air cleaner. You just need to find out what each of these things needs and run a hose. The difference between the ported and manifold vacuum is the way they respond to acceleration.When you floor it. the manifold vacuum drops and the ported vacuum increases. The distributor goes to ported, this advances the ignition on acceleration. The really big tap goes to the PCV valve, that one is pretty easy. Now it is a question of what else you want to control. And you can plug any you are not using.

When vacuum increases does that mean you have more of nothing??

 

[mtnwhlr]

If you can wait untill sunday I can look at mine and let you know where all the ports go.

 

[Swilliams]

My opinion is the motor craft also. You can buy a rebuild kit and do it yourself for less than $50. Just be sure and soak it for about 24 hrs, to clean any buildup off, before you rebuild.

 

[mtnwhlr]

IO, I do have the 11x17 wire schematic and it was great when I was putting stuff back together. I have a Haynes manual, but it does not show the actual ports on the carb for placing the lines back on, too general. I think the service manual is going to help me get these lines on and ports plugged, that need plugging. Thanks again.

JD

Ok I hope this helps you, on the back of the carb there are 3 vac ports the biggest one is for your PVC the small one next to it goes to the chock pull off and the other one is pluged on mine. Now on the side facing the valve cover there is a small one kind of in the middle it goes to the dissy and the two big vents hook together and goes to the charcoal canister. Then the small one on the front by the adjustment screws goes to the CTO switch on the side of the intake.

 

[gadawg31]

mtnwhlr, would you see any reason why I couldn't/shouldn't plug the the small port going to the CTO? Also, I have the distributor hose done, the PCV I have; however I believe I need to also run a big hose from the PCV valve to the chock pull off. Does this sound about right? All others, I believe I can plug, since the PO has stripped this jeep of anything emissions related. Thanks.

JD

 

[mtnwhlr]

mtnwhlr, would you see any reason why I couldn't/shouldn't plug the the small port going to the CTO? Also, I have the distributor hose done, the PCV I have; however I believe I need to also run a big hose from the PCV valve to the chock pull off. Does this sound about right? All others, I believe I can plug, since the PO has stripped this jeep of anything emissions related. Thanks.

JD

If everything has pretty much been removed all you should need is the vac. to the dissy and the one to the PVC the one to the chock pull off and it should be hooked to the small port in the middle next to the bigger one for the PVC.

 

[JimsCJ5]

I'm surprised no one has recommended the Weber set-up. Is the 2100/2150 that much better?

There's someone on eBay selling the whole shebang for $229.

Jeep Genuine Weber 32 36 Dgev Electric Choke Carb Carburetor Kit K551 WK551 | eBay

 

[harleydragon]

on another forum that I am on,I read of a lot of guys having troubles with webers

 

[JimsCJ5]

I've read good and bad things about the Weber. I have run them before without issues on other vehicles.
I think I read the 2100 is better off-road but the weber is better hot-rod HP type of carb.
I am mainly interested in reliability and MPG at this point...

 

[harleydragon]

yeah,supposed to be a good performance carb.But getting them right and then,them staying right seems to be the problem.I think they are on the bottom of the list as far as trouble free operation and fuel economy..2100 & 2150 motorcraft seems to be everyones favorite in those categorys.Best I ever had on a AMC 258 i6 / 4.2l was a holley

 

[caveman]

I had the weber carb on mine untill recently and the only problem i had with it was in off camber and steep situations. Otherwise it performed like a champ. Swapped it out for the motocraft 2100.

 

[NorthwestCJer]

Poor mans fuel injection.. MC2100 1.08 ventury motorcraft.
I off road and my jeep can run on its side.

Here is a video a few years back of a buddy of mine. 360 amc 2100 1.08.
This is how they perform!
Waycrazy's CJ5 tricks - YouTube

Here is a photo bucket link to my 84 CJ7 mc2100 retro on AMC 258 i6 / 4.2l .
84 Cj7 Photos by JeepSparky | Photobucket

Make sure you only use a 1.08 carb. anything bigger will give you problems.
Check out Daytona Carbs 386 427 7108
I have had great luck with parts from these guys.
You will also need to lower the jets. I run 44's on my AMC 258 i6 / 4.2l .
There is a few more little tricks before bolting it on. but help is here if you need it.

Most people have Webber problems because it is a progressive 2 barrel. meaning its a one barrel then the second kicks in. Tuning can be tricky but once people get to understanding it, they do well.

Good luck

 

[JimsCJ5]

Holy Cow! We don't plan on doing anything that extreme at least not right away. That carb does run on it's side!

Thanks for the info... I think we are leaning towards the 2100.