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fj40 32/36 weber

Discussion in '40- & 55-Series Tech' started by talkinggoat, Oct 28, 2003.

  1. talkinggoat

    talkinggoat

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    i have a 32/36 weber on a 2f that i have been having trouble with for some time, now. i have limited all of the symptoms and problems down to the carburetor:

    it all started with the engine running rough until it warmed up, and, even then, it would still hesitate and misfire through the carb. i found that the carburetor was tuned far too lean from the factory. i installed larger idle jets and worked with the choke. this half way fixed the problem. on a hunch, i forced the carb to drop more fuel by closing the choke off and making the engine run extremely ritch. this cured the problem of it firing through the carb, but, as you may or may not know, the 32/36 is a progressive. while it solved the problem on the first barel, it didn't on the second. the choke was open when the second was engaged casuing the exact same thing to happen that the first barrel was experiencing. i soon corrected the problem with the first barrel by placing a larger main jet in the fuel stream. this caused all hesitation and misfiring to cease with that barrel only. the second was still having trouble, even though i placed a larger jet in it, too. a couple of weeks later, while looking into the carb durning function, i noticed that there is only one accelerator pump for both barrels that squirts fuel into each at the same time. the second barrel holds this fuel until it opens, at which point, it hesitates and fires through the carb. i seemed to have corrected this by removing the ability for it to deliver fuel to this barrel. it still hesitates, but it does not backfire anymore. i know that it is not a problem with the accelerator pump itself. it is delivering fuel to the carb.

    last night, i had the choke stick closed on me. this may have shead some more light on the problem. while the choke was closed, the cruiser would accelerate without ANY problem. it ran great, until it was choked out... what i am now thinking is that this carb is too small and incorrect for this engine. it is not delivering the correct ammount of fuel that it needs to run properly. is there anyone out there that has had a similar problem with this carb? any advise is appreciated.
     
  2. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    Your assumtion of the situation is correct.
    This is a smaller cfm carb than stock from what I have observed, read and been told. This is going to run lean on your engine. I would get a good stock rebuilt from one of the carb gods out here, or get a 38/38 weber. I have had decent luck with them on the ten or so F and 2F trucks I have installed them on...

    -Steve
     
  3. jm

    jm

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    Poser has hit on something! The 32/36 is TOO small for the cruiser. 38/38 should make a world of difference... however there are people running the 32/36 without problems. Are you running a fuel pressure regulator? If not you weber may not be happy... I think 3.5psi is the max recommended and mine (38/38) is happier at 2.5psi... had all kinds of running problems until the pressure was brought in line.

    jm
     
  4. toddslater

    toddslater

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    I guess I'll have to differ with the above...awhile back this was what I cyphered using standard carb/cfm sizing.

    My .02 then and now on the subject.
     
  5. dd113

    dd113

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    I guess I'll have to differ with the above...awhile back this was what I cyphered using standard carb/cfm sizing.

    Quote:
    Using a CFM calculator, I came up with the figure that our little beauties would need up to ~304 CFM (max) to get them to spin at 4,000 rpm. And dare I say ~380 CFM at 5,000 rpm. If this was a NASCAR cruiser, heaven forbid, that could spin all day at 5,000 rpm then by all means yes to the 38/38 or 390 CFM weber. Since I doubt that this would be the case and quite possibly 98% of your engine spinning should be at or well below the 4,000 rpm range, the 32/36 or 300 CFM would be more of an "ideal" fit. However, in our tractor motored Cruisers you probably won't notice the diff.

    What is true and I have notice of motors that are less "tractor like" is that if you are over carburatted, you will lose low end torque and throttle response.



    My .02 then and now on the subject.


    Wow Todd, my theory exactly; just never backed it up like that.

    32/36 should work well but it does not. Never has. Not sure if it is the progressive nature of the second or what. I quit fooling with them. The 38 works fine overall but it is more of a PITA than a result. It will run better overall and will give you the feeling that you have more power but it will take away the torque.

    Best bet for a stock motor is the stock carb. Not to say you cant mess with the stock carbs a bit. 75/76 are the best.

    I run Hollies on all my trucks but I would never install a holley on a customers truck. Too much time and money getting ti to run right. Once it does it cannot be beat! Holley is a 350 CFM turned down to around 320ish CFM.