Carter BBD bad hesitation problem

Tiny
KS78CJ
  • MEMBER
  • 1979 JEEP CJ7
  • 4.2L
  • 6 CYL
  • 4WD
  • MANUAL
  • 140,000 MILES
Hi all,

Rebuilt my 1979 Carter bbd on the 258 but have had endless issues trying to get it to run right. First it was warm-ups (fixed) then it was power. Which I seem to have a bit now. But I cant get it to idle consistently and there is a bad hesitation when trying to pull out in first gear along with any low rpm shifts. I need to floor it to get it to not die out. Any thoughts? I just did the wires and plugs and the dizzy ( which is running manifold vacuum) and just recently put in new PCV hose. Getting good fuel to carburetor so I am quite sure its just a carburetor issue. Trying to get the Jeep running before work on Monday lol.

Thanks for any replies!
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Friday, May 17th, 2019 AT 7:01 PM

19 Replies

Tiny
CJ MEDEVAC
  • EXPERT
Just for giggles,

Think you could post good pictures of the left and right sides of your engine with the breather removed?

Also, lets lay the hood back on the windshield frame and remove the breather for a few good overhead shots.

The better the light the better!

Sometimes I can spot problems in the pictures, There's been 40 years that people could have monkeyed with stuff!

I presently have a 1946 and a 1977, I have upgraded many things on the 1977 to be like a 1979.

I've never had nothing but CJs ever since I was allowed on the road in 1981. I consider the 1979 model the "peak" of the CJs!

We'll continue on after your next response!

Nice to meet you!

The Medic
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Friday, May 17th, 2019 AT 7:58 PM
Tiny
KS78CJ
  • MEMBER
Hi CJ, thanks for the help. Hope these photos are what your looking for.

I got it to idle okay today redid the gaskets under the carburetor. The weird thing is the mixture screws are both backed way out. Completely maxed out. Wasn't like this prior to rebuild.
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Saturday, May 18th, 2019 AT 5:18 AM
Tiny
CJ MEDEVAC
  • EXPERT
I'm going to give it to you as straight as I can.

Pic 1) Obvious things I see. There are reasons why they should be like 2, 3, 4

Pic 2 and 3) Return line (with a few bells and whistles)

Pic 4) 1979 PCV is on the left.

Pic 5) My 390

I've since replaced my intake manifold and installed a 390 Holley on mine. Doing so was very expensive, I do get 18 MPG (I had made up my mind I would make a MPG improvement no matter what it costs!)

Your carburetor (the Carter BBD) is a great system!

However,

The carburetor is 40 years old, it has 40 years of wear on many of the parts.

Even buying a re-manufactured carburetor may still leave you with worn parts reused with in it.

There are some tedious adjustments that need to be made, sometimes the re-builder does not make these "tweaks" to the reman.

The average Joe with limited knowledge will build it wrong or damage a part without knowing it.

I'm almost embarrassed to make this suggestion, I have suggested this many times and so far, have always gotten good results (with local Jeeps)(With 2carpros forum fixes).

Seems that the Jeep Carter BBD carburetor is not made domestically anymore, remans are about all that are available. And you still have an "old" caburetor!

Over the pond, they are making new ones! They work great! They adjust as they should!

It's been a while since they hit the market, they have gone up in price a little. They are still way cheaper than a reman, but just a little more than a rebuild kit. It's ready to go!

If you go this route, I will be glad to aid with installing it and tuning the Jeep properly!

I've looked over the whole bunch, this would be my best suggestion. See this link.

https://www.ebay.com/itm/CARB-CARBURETOR-TYPE-CARTER-ENGINE-FOR-JEEP-WAGONEER-BBD-CJ5-CJ7-2-BARREL-6-CIL/151969443561?hash=item236215aee9:g:jSQAAOSwr lYqrIO

What do you think of this plan so far?

The Medic

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Saturday, May 18th, 2019 AT 7:52 PM
Tiny
KS78CJ
  • MEMBER
Sure I am interested. Only problem is I live on Canada and a lot of the sellers wont ship there. I sent the seller an email but I doubt he will respond.
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Sunday, May 19th, 2019 AT 6:53 AM
Tiny
KS78CJ
  • MEMBER
Also the red line you see is for the breather hot air intake just wasn't hooked up with breather removed. The PO never had a fuel return line connected I see where they cut it though I will try to hook it back up.
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Sunday, May 19th, 2019 AT 10:18 AM
Tiny
CJ MEDEVAC
  • EXPERT
I have no clue about what "On Canada" is all about, My bestess 5 minute guess is "Ontario Canada". Why that could be considered a bad place for mail, again, is beyond me.

Email him back and explain that CJ MEDEVAC on 2carPros. Has been recommending the carburetors he sells. If he cannot deliver, we'll be forced to find another source that can!

The return line and correct fuel filter prevent the needle and seat from being overpowered with fuel pressure. Meaning fuel could be forced into the carburetor (overfilled) when the floats should have stopped it at the proper height and any overage being recycled to the tank.

Want me to look for a different source for the carburetor? You want to try him again? You want to look too?

The Medic
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Sunday, May 19th, 2019 AT 11:51 AM
Tiny
KS78CJ
  • MEMBER
So I was digging around today and since I need the jeep for work since I drive it daily I was able to get a hold of a Weber 32/36 for cheap. Funny how things sometimes work out just when you need them. I installed that on the jeep and its running great which was awesome to see. Back on the road for the summer woohoo. Supposedly good carbs for jeep from what I hear. Don't like getting rid of the carter but it will be back one day but for now ill stick with this. As long as I can drive it there is a smile on my face!
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Sunday, May 19th, 2019 AT 4:47 PM
Tiny
KS78CJ
  • MEMBER
Thanks for the help!
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Sunday, May 19th, 2019 AT 4:48 PM
Tiny
CJ MEDEVAC
  • EXPERT
I reckon to each his own!

I ran a Weber 32/36 progressive for maybe a year. I never could tweak it to gain more MPGs (it's literature promised a 20% betterment).

After a few books (manuals) and pill organizer full of different sized jets, squirters, and various other tuning parts I threw in the towel and began investigating a 390 Holley.

This may help, I need to re-write it specifically for a 258, so let's disregard the 304 translation! I answered that one a long while back.

https://www.2carpros.com/questions/jeep-cj7-1985-jeep-cj7-stalls-when-hot

With the Weber, you are going to find that the "ported" vacuum to the distributor's vacuum advance will work the best.

I also prefer manual chokes, there's normally less to go wrong and "stick". I'm the one in charge of when it's on, off, cracked open!

Pics below were my records as to how I tried to tune the ole Weber and did other Jeep maintenance along the way.

As you can gather I'm not the one to give Weber advise!

The Medic
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Sunday, May 19th, 2019 AT 6:11 PM
Tiny
KS78CJ
  • MEMBER
Hi Medevac,

Bumping this tread lol, was able to get a Carter off eBay, not to bad a price. Got it mostly tuned up, just can't get rid of a stumble upon hard acceleration from low rpm's. When accelerating from 1000+ rpm's it accelerates hard, but when coming from idle speed and flooring it, it stumbles (wont die) and then picks up(this is all in gear). I have gone through it fully and have the step up piston set to 0.035 ish lol, accelerator pump I have been playing with (currently at.5in as specs say) and mixture screws set at lean best idle and timing at 9 deg. Not sure where the problem would lie?

Could it be floats or am I simply just missing something. No vacuum leaks. Also, I have sprayed carburetor cleaner all over the base. Idles really nice and cruises nicely also.

When going to wide open throttle in neutral it will rev up fine but when it goes back down to idle the idle drops then picks back up? As though its running really rich.

Thanks for any replies, just want to get the Jeep out in this nice weather. :)
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Thursday, May 21st, 2020 AT 5:07 AM
Tiny
ASEMASTER6371
  • EXPERT
Good afternoon,

Does this have an EGR valve?

What are the points set at?

https://www.2carpros.com/articles/engine-hesitates

After the points are set to the correct setting, I would set the timing at 12 degrees before top dead center. With the age of the Jeep, I would advance it a little for timing chain wear.

Roy
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
KS78CJ
  • MEMBER
Hi Roy,

Thanks for the response, I will give that a try. I brought the timing up before and it defiantly decreased the rpm drop, I just brought it back down because the idle is really smooth at 9 deg. Would I need to give more of an accelerator shot to compensate for the increased timing? Or just see what it likes?

I will check the points, no EGR.

Thanks
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Okay, keep me updated.

Roy
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
KS78CJ
  • MEMBER
I will update tomorrow, wont be able to today. Thanks

i do think it is carburetor related because I recently had a Weber on there (felt under-powered so I went back to the good ol Carter). It shouldn't be float if its idling fine and I have played around with the accelerator pump, so I am just not sure if it's too lean or too rich. When slowly moving accelerator pump it does not shoot for the first bit of movement and then starts spraying. Should it be a constant spray fully through throttle movement?

Thanks again.
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
The pump should shoot fuel as soon as the throttle is moved.

Check the check ball at the bottom of the passage. It may be bleeding down and need to be primed before shooting fuel.

Roy
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
KS78CJ
  • MEMBER
Thanks, I will take a look and shoot you and update. Priming the pump would be new to me, never heard of that before.
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Always glad to help.

Roy
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Thursday, May 21st, 2020 AT 12:28 PM (Merged)
Tiny
KS78CJ
  • MEMBER
Seems as though the float was way too low. About half of what it should be, stumble is basically gone, runs really well. Also primed the accelerator pump and that seemed to help get some air out of the passage. Thanks for the help.
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Sunday, May 24th, 2020 AT 6:36 AM
Tiny
CJ MEDEVAC
  • EXPERT
Well,

I never got notified when you returned?

I do have a wrong to right!

Maybe everybody that saw my other pics didn't use them!

ASEMASTER6371 thanks for jumping in, it's not good when your (my) client thinks he's been abandoned!

See if this new pic makes sense, also throwing in a current pic of Mr. Jeep.

The Medic
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Sunday, May 24th, 2020 AT 10:42 AM

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