CJ5 Carburetor Issues

Guys, I'm wondering about the carburetor on my Jeep and am having thoughts of replacing it although I don't know which is the best choice.
I haven't been able to find a lot of information on this subject on the web which is straight forward without someone trying to sell theirs as the best available. I have a 1 barrel Holly model 1940 on my 232-6 cyl, I'm experiencing the usual tough cold starts, coughing and missing while driving until it warms up, then it just seems to run under powered.
I'd really appreciate it if someone could pick up on this and offer some ideas on what I should look for in a replacement or would I be best to rebuild what I have and run with it is. Thanks

 

Can't help either.
Welcome from central Va

 

it more than likely came with a carter yf carb. fromthe factory.a good upgrade would be to put a 258 intake manifold on and put a 225 v6 carb on it which is a 2 barrel set up.i did this many years ago to a friends 1972 cj 5. one other thing to check on is the heat riser on the flange of the exhaust manifold. if it is rusted open the intake manifold is not heating up and will cause driveabilty problems in cold weather.

 

Thanks, I check into it.
Is that 225 v6 carb a Carter carb? It looks like my stove is in good shape.

 

How about a 2bl intake from a 258 along with a Motor craft 2100. I use this on my 258 I-6 and it gives great starts, no sputter. Easy to setup and parts from any FLAPS.

Parts can be purchased or pulled from a wreck yard.

 

Thanks for the input. I'll definately look into it.
I had given some thought to that, but guess I wanted some feedback from a user. Are you happy with that carb? Are you getting a decent amount of power?

 

I am very please with my mc2100 on my 232 I6. Works great.

 

Thanks again. Looks like I'll go on the hunt for a carb & intake to fit.
I'll let you know how things turn out.

 

The 225 carb is a Rochester 2G. Bolts right on to a 258 manifold. I ran one on my 80 CJ-5 for a couple years and it seemed to be no better than the stock Carter BBD. So when it came time for a rebuild, I put the BBD back on. The Rochester I ran came from a 307 Chevy and that may or may not make a difference over one from a 225. They are simple carbs without metering rods as in the BBD. You have to fiddle with the linkage a little to adapt to a AMC 6.

 

Thanks to you too 80cj. I just returned home from a local boneyard here in MN. I had no luck with the mc2100 carb. did see a lot of 1 barrel carters but I passed on all. Guess I'll keep looking. I figure I'll do a bit more research and keep the BBD in mind. In the meantime I might give a rebuild kit a go with the Holly 1940 and see where it gets me.

 

someone has kidnapped sparky and taken over his computerR)

 

Note that that is the 2V (2 barrel) 232 and 258 manifold that will accept the Rochester. A 1V would have come stock on a '75 with a 232 or 258 and have a 1V Carter YF carburetor. A 1V Holley could be either a Holley replacement carb (sold at one time specifically for replacing the Jeep carburetor) or a junkyard replacement.

If you have the 1V manifold, I'd suggest either sticking with a 1V carb or using the later manifolds with the 2100 (as suggested above), the Weber progressive 2V (available as a kit), or TBI (throttle body fuel injection, also available as a kit or from junkyard parts).

 

i'm a bit confused!
i have a stock 75 cj5 with an inline 258 6.
would the v6 carb or the motorcraft 2100
just bolt right on?
or would i have to change the intake manifold?
thanks
iowa

 

No, neither will bolt on.

You could
a) change the manifold or
b) buy an adapter.

I don't know if the adapter is available for the Rochester 2GV or the Carter BBD, but it certainly is for the Motorcraft 2100.

 

hi tim
so i buy the adaptor and the carb
and it will simply bolt on to my stock manifold
and work like a charm?
if so, does 4WD.com sell both?
iowa

 

To clarify for 5foxes, I run the 2100 on a 1974 cj5 w/ original 258. The intake is a 1bbl intake -stock, with an adaptor between. My local wreck yards aren't the best, and I'm still looking for the 2bl intake. The improvement over stock was night and day even with a 1bbl intake.

Another note: added a HEI distributor. Highly recommend this upgrade.

 

i run another combination on my '75 258.

i retained the stock intake, and used a weber k550-14, which is the progressive 32/36 carb made for the one-barrel (1-V) manifolds. it comes with the adapter to mount it to the manifold. i happen to like the combination, even though others have stated that they don't like the 2-bbl carb being placed on a 1-V manifold.

there are adjustments that need to be made to dial it in. first and foremost, a fuel pressure regulator that operates in the 0 to 4 psi range needs to be added after the fuel filter. the factory float level was too high, so i lowered it and solved my flooding problems.


as mentioned in the previous post, the HEI conversion is excellent, and i highly recommend doing it. i "probably" could have retained my carter yf carb if i had converted to HEI before switching carbs, but i didn't know about it at the time. the jeep no longer has low speed miss/idle problems, runs smoothly, and gets better throttle response.

wally

 

A quick note....The 2g series from a V8 will be larger than the V6 with a larger/different mounting bolt pattern.

 

Gee, thanks a bunch garbageman, wally & jeepdaddy! This is awesome information! Now I'm going to look into the HEI distributor & consider rebuilding and sticking with my Holley as a first step. I appreciate it.