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Replacing the carburetor

Replacing the carburetor

NEPACJ7

Jeeper
Posts
20
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Location
pennsylvania
Vehicle(s)
1978 CJ-7
304v8
automatic transmission
quadra-trac
I am picking up a 1978 CJ7 with a AMC 304 , GM Turbo 400 mated with quadra-trac, and a holley 2 barrel carb on the stock amc intake. The carb is bad, jeep starts but dies after 3 or 4 miles. The owner all ready informed me of the carb needing to be rebuilt or replaced.

For a 1978 CJ7 , if it were the original carb, would it have been manual or electric choke? What I am needing to do is get a carb that will fit the stock amc intake that I can bolt right on, hook up the lines and I am done. I have a budget of about 225 dollars including any core charge. I have no issues buying used, and this would only be a temp fix until I have enough saved up to change the intake and put on a 4 barrel carb, but I need to have the jeep up and running to drive to work.

I know there is the motocraft 2150, carter, rochester, and holley but most of the carbs in my price range are none of those brands. Besides the carb itself what else will I need to put one in? I am waiting on an e-mail from the owner as to what model holley is on it which should narrow it down to the type of choke unless there was not really any option in 1978. I'll be looking on youtube for how to change a carb out, I've never had to do that as I never have had carb issues in the past. I would appreciate any help and also if more info is needed, just let me know!
 
The original carb would have had an electric choke. If you are waiting for a 4bbl swap, just rebuilt the Holley. When you get the 4bbl, use the 2bbl as a door stop.
 
Thanks for the information! I actually just found a company a few minutes ago that sells rebuilt motorcraft 2100 carbs for $158 with no core charge up front unless you are not returning the old carb in which case it is an additional 98 dollars. They also pay for the core return shipping. The plan is to put on the carb, bleed the brakes and drive it home from the guys house.

Once here I have to replace the o ring in the Transmission filler tube as well as the Transmission pan gasket. Once that is done I'm good to go. After searching youtube I have found no information on swapping out a carb and I am thinking it's about 40 minutes, especially if this carb is set up and ready to go. I thought about eventually putting in a 360 next summer and doing fuel injection but I do not and will not go back to something that requires o2 sensors as direct fits are a rip off cost wise for what they actually are.
 
So what's with O2 sensors. They are what they are, which isn't cheap. Plus they last a long time. You should try getting a NOx sensor.

40 minutes might be a on the low end for a carb swap. Unless replacing with the exact same carb, there will probably be issues.

Should have mentioned that dying after a few minutes sounds like a fuel delivery issue or ignition issue, not a carb problem.
 
The original carb would have had an electric choke. If you are waiting for a 4bbl swap, just rebuilt the Holley. When you get the 4bbl, use the 2bbl as a door stop.

Sorry but there were no wires hooked up to the AMC 304 that came with my 1978 CJ5 . There is a heat tube from the manifold to the bottom of the thermostatic coil that controls the choke. As the motor heats up the coil relaxes opening the choke valve.
 
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Some chokes use the heat stove only, some use the heat stove and electric, some use electric only. I figured by 78' they were the combination type. I prefer electric only. Manual chokes are for lawn mowers only.
 
The o2 sensors on my current vehicle run over 200 dollars each for oem direct fit and it takes four. I'm going back to a 70's Jeep because it's more simple, easy to work on when all you have is 1 or 2 days out of the week do do work and parts are still extremely cheap.

Worse case scenario I can trailer the Jeep and do the work here, I am familiar with just about everything except for messing with carbs. Also I have found that on things I do not know, Jeep owners on forums like this are more willing to help out vs. the forum for my current vehicle.

It is definitely the carb on this Jeep, it's just tired and worn out, a rebuild might not even work on it so it would be easier just to throw on another one then try and rebuild and it not work.
 
Once I get the e-mail from the current owner about the holley that is no it now I'll know exactly how it is set up. Thank you to everyone that has responded so far!
 
If you need a electric choke for your carb they are pretty easy to wire..
 
There is not an electric choke on it, nor is it manual, it has the hose for recirculating the air from the intake after it is heated. Also The only thing that can be made out on the carb is list and you can not read the numbers after that, so I am having a friend look at it once I get this Jeep and either we will rebuild it or I'll just throw on a mc2100 and be done.
 

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