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Rochester 2G won't idle and stalls if not partially choked

Discussion in 'Early CJ5 and CJ6 Tech' started by OrangeCJ5, Feb 1, 2016.

  1. Feb 4, 2016
    uncamonkey

    uncamonkey Member

    Greeley CO
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    I was back playing with my brothers CJ6 and it wouldn't idle well either. So I dug into the carb a bit. Whoever was in there before installed the emulsion tubes wrong. There is a way they go in correctly and these wern't so the gasket would never seal correctly.
     
  2. Feb 4, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    What are the emulsion tubes? Is that another name for the venturi assembly?
     
  3. Feb 4, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    When you try driving it does it have plenty of power, or does it seem weak? Are all rubber vacuum hoses rated for vacuum? Have you tried turning the distributor at all as in trying to advance the timing a bit?
     
  4. Feb 4, 2016
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    What's the number on the carb?
     
  5. Feb 4, 2016
    Dave B

    Dave B Frankenjeep '67

    Northern Minnesota
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    Mike, it's good to keep an open mind and try to start with a clean slate (if necessary). You have to ask yourself all the questions that may or may not seem directly tied to the problem. The question list is a challenge of your own inventiveness.

    I'll start with "foolish" question #1, which stems from pertronix installed in distributor--Is the new spark plug wire set a proper match? More important than my question is your questions based on your projects specifics which only you can puzzle through. I'm no mechanic, but I'm not afraid to question/turn over every rock. And you can "luck" on to some answers--sometimes!

    It's very likely that YOU will be the major player in solving the problem, if you stick with it and use the reply input as a catalyst for research . The encouragement--Oh, the satisfaction in the solved problem! I question if I should send this --but maybe, just maybe it will help. --Best to you --Be sure to respond to Focker's second plea, which is one of those important questions for input help.
     
    Last edited: Feb 4, 2016
  6. Feb 4, 2016
    uncamonkey

    uncamonkey Member

    Greeley CO
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    If you pull the venturi assy off, under it there a two brass tubes that have a bunch of holes drilled in them. After I thought about it they have no effect on the idle circuit as they are mostly there to help meter the higher speed fuel flow.
    Sorry.
     
  7. Feb 4, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    Sorry it took me so long. 7041186.
     
  8. Feb 4, 2016
    Dave B

    Dave B Frankenjeep '67

    Northern Minnesota
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    Nov 10, 2009
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    650
    7041186 = '66-71 Jeep (Buick V6)
     
  9. Feb 5, 2016
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    AMC, JEEP - Specification I.D.-E
    [​IMG]

    Footnote 17 = From Gasket to top of float at toe.
    [​IMG]

    [​IMG]

    [​IMG]
     
  10. Feb 5, 2016
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    cordele, Ga.
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    Focker If I remember reading back, the OP is using a brass float. The one you post is not the proper measurement for the brass one. The brass float is shown in Fig. B in the instruction sheet.
     
  11. Feb 5, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Have you had the top of the carburetor off while gas was still in the bowl? If so how much gas was in there? At least a rough idea anyway?
     
  12. Feb 5, 2016
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    Good catch Walt... Fixed.
     
  13. Feb 5, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    Yes, I'd say it was at least 2/3 full of gas.
     
  14. Feb 5, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    I don't think the float setting is an issue, or the issue then. It's able to let enough gas in and it would appear from your description that it's not flooding over either. Of course the proper setting is very important to have. It seems you are reasonably close enough to just have to fine tune the setting.
     
    Last edited: Feb 5, 2016
  15. Feb 5, 2016
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    When looking down into the carb, pump the accelerator, do you see 2 nice streams of gas or dribble?
     
  16. Feb 5, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    Here is what I know for 100% absolute certainty:
    1. The gas tank is clean on the inside
    2. The fuel feed and return lines are in perfect condition
    3. The fuel pump is working perfectly
    4. The fuel coming out of the pump and into the carb is clean (glass filter)
    5. Changing the idle mixture screws from 1.5 turns out to 3.5 turns out had no appreciable difference (that has to mean something)
    6. Jeep will start and run when cold (choked and on the fast-idle cam)
    7. Jeep will not run when choke is open
    8. Hose to PCV valve is brand new so it's not leaking
    9. There is almost zero play in the throttle shaft
    10. the idle mixture screws are in perfect condition (no ridges)

    Here's what I am not 100% certain of:
    1. float setting
    2. timing
    3. engine compression
    4. that all the tiny passages in the carb are clean

    I am willing to pull the carb, get it cleaned somewhere that can assure it's super clean and reassemble it. What if anything should I do before that? I am getting my hands on a timing light and a compression tester today.

    I appreciate all the help and ideas. I love these old Jeeps and the puzzles they present
     
  17. Feb 5, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    2 nice streams
     
  18. Feb 5, 2016
    OrangeCJ5

    OrangeCJ5 Sponsor

    Taylorsville, UT
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    I did that, if my hand covers the opening it will stay running. As soon as I move my hand it sputters and dies.
     
  19. Feb 5, 2016
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    I wonder if you should disconnect the automatic choke, do it manually and see what happens?

    Did you remove the fuel filter at the carb's fuel inlet? Those get gummed up and IIR, they must be installed pointing in the right direction.

    If you happen to pull the carb for another cleaning, buy an Ultrasonic Cleaner from Harbor Freight and do it...Plus it's worth having around.
     
  20. Feb 5, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    In addition to the above questions, is the problem that it only won't idle or just won't run at all when warmed up, even if you rev it up?
     
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