Choke / WOT issue Carter AVS

Engine, Transmission & Driveline

  1. Stoffauge

    Stoffauge Member

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    Hello all together.

    I bet there were lots of carb issues but I hope to challenge you with this one!

    71 Sport Fury 383 CARTER AVS 4BBL

    Ignition checked and reset to 8-9 degress before tdc

    Carb rebuild and adjusted (fast idle speed cam, vacuum kick, acc pump, sec throttle lever, sec air valve etc pp)

    Problem 1: CHOKE valve goes wide open right away while cranking cold engine

    Car won´t start without keeping choke valve almost closed MANUALLY BY HAND because it wide opens while cranking the cold engine and the engine dies right away ! Starts without any problem if holding choke valve almost closed by hand till it warmed up and runs good after that.

    Problem 2.

    WOT not possibe without backfiring or spitting some gas out of the bowls. Did turn out the mixure screws while checking for highest vaccum via gauge (plugged in at choke outlet vaccum port . Got 15hg while idling) WIth choke plugged off WOT with the new screw adjustment ( very far turned out ) is almost 100% with no backfire and good but with choke assembled and attacjed WOT is doing hickups/dies and sometimes backfiring after 2-3 times WOT in a row.

    Hope I did describe it detailed enough. If not just ask .

    I am VERY excited what you guys will tell me because I am at the end of my carb knowledge.

    SO lets go :D

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  2. CBODY67

    CBODY67 Old Man with a Hat

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    #1 -- Where is the automatic choke thermostat? The choke plate is offset so that air flow will pull it open, by design, but without the automatic choke thermostat to modulate the valve, plus the vacuum break pull-off, you get what you've got. It should be in the well on the rh side of the intake manifold, with its rod being in the circular slot that attaches to the choke plate's shaft.

    #2 -- The idle screws only affect the idle mixture, probably below 1000rpm and before the main system starts flowing fuel. The choke linkage has a WOT lock-out feature on it to prevent WOT while the engine is cold and before the choke is open a good bit.

    All for now,
    CBODY67
     
  3. 413

    413 Well-Known Member

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    MOve the accerator pump linkage. To the outer Of the 3 holes. Is the accelerator pump pumping fuel?

    You are missing the choke thermostat. Choke will not close on its own, you need this part. 1970-1971 383 & 440 AVS the same, Holley different. You have the choke pull off rod in the wrong hole, it goes in the slot. And choke goes on the hole where the rod is now.

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  4. 70bigblockdodge

    70bigblockdodge Old Man with a Hat FCBO Gold Member

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    I was going to say your divorced choke is weak, but it's missing so there's your problem.
    The backfiring at WOT is most likely ignition related. Without the choke being held open by the divorced choke and the vacuum falling off at WOT that could also be a issue.
    Your timing should be set more like 10-12-14 degrees BTDC initial or around 35-36 degrees total at around 3500 rpm. You will get better mileage, more throttle response and power. This is as long as your not getting any detonation.
     
  5. Stoffauge

    Stoffauge Member

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    Good morning guys

    Hoped to wake up to a bunch of nice answers :)

    First to say: How you see the carb, is how I got it. I never ever had anything to do with carbs before and thats why I didnt notice that something is missing. I put it back together like it was before so I took all the issues with me. Hope that makes sense :)

    So whats the part called excactly that I need ? Automatic choke thermostat or electric choke thermostat or is it the same?And that part goes in the slot where the choke rod is right now ? Hope I can get it seperatly.

    @413: The acc pump is new and all gaskets. How do I check if the acc pump is pumping fuel? With the outer hole you mean the one on the very bottom right?

    Ignition: Gonna check that later when the carb is complete and advance it more to 12-14. (Don´t have lightning gun so I did it manually with the scale on the vibration damper)

    Ok I am happy to hear a part is missing instead of doing biiig mistakes.

    Thanks for now gonna check for that part and keep you updated.

    F



    EDIT: Guess I found it . Damn thats pricey! Hope to find a aftermarket part maybe...
    https://quadrajetparts.com/divorced-choke-carter-p-2354.html
     
    Last edited: Feb 18, 2021
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  6. CBODY67

    CBODY67 Old Man with a Hat

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    Thanks for that link. Price in USD seems about right to me, all things considered.

    CBODY67
     
  7. Welder guy

    Welder guy Old Man with a Hat FCBO Gold Member

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    I have a used one sitting on the shelf in my garage. I believe it’s from a 70 fury. I will take a few pictures of it . Maybe it will work for you. It’s in pretty good shape.
     
  8. Welder guy

    Welder guy Old Man with a Hat FCBO Gold Member

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    Well I do have one but it’s for a Holley, I’m not sure if it will work properly on your Carter . I don’t know if the linkage is the same . E43DF70D-7A82-443F-81B6-0A6BE98194E2.jpeg E6926B29-E503-4823-8F9F-8D924DAE06E7.jpeg 76F421CE-ED38-483A-9260-052182B4F244.jpeg AFE6C430-A842-42EA-8884-03E2C22391F1.jpeg 3CEE5E3D-8197-4FEC-ABD5-A534F56C989C.jpeg 5E0DA51C-C36B-4DAC-B68E-6844B44F0473.jpeg 5115BED8-1458-40CE-B774-8172635BCC88.jpeg 3E52AA4D-C156-40A9-93B4-BB9E9DEE86FD.jpeg
     
  9. Welder guy

    Welder guy Old Man with a Hat FCBO Gold Member

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  10. CBODY67

    CBODY67 Old Man with a Hat

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    With the "Holley" imprint, is that a Holley-brand thermostat for a Carter AVS?
     
  11. Welder guy

    Welder guy Old Man with a Hat FCBO Gold Member

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    Well I’m guessing it’s for a Holley
     
  12. Welder guy

    Welder guy Old Man with a Hat FCBO Gold Member

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    I just don’t know for sure
     
  13. 413

    413 Well-Known Member

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    That one is for a 67-69 intake and a Holley carb. Won’t work no-how.

    Compare the bends in the rod to the one in his link above. Very different Carter to Holley choke thermostats.
     
    Last edited: Feb 18, 2021
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  14. Dana

    Dana Woodruff Carburetor Specialties FCBO Vendor

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    ^^^^this^^^
     
  15. Stoffauge

    Stoffauge Member

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    Morning guys,

    called a buddy yesterday and he has a good used choke thermostat from the same Carter AVS. Guess that will work.

    After it´s installed I am gonna advance the timing a tiny bit more and see if the WOT problem is getting better or not :)
     
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  16. Stoffauge

    Stoffauge Member

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    Ok guys attention :D

    Checked my fsm again because couldn’t believe I’ve overseen the choke thermostat and not noticing that it’s missing and boom !: no damn choke thermostat on one picture and no word said about also !

    So what’s going on here ? Don’t I need that part ? But then why is my choke not working ? Weiiiird!

    Looking for help :)

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  17. ceebuddy

    ceebuddy Well-Known Member

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    Stoffauge, the divorced choke thermostat spring is not an integral part of the carb, but is attached to the choke well in the intake manifold. It actuates the choke shaft via a steel rod that goes in the hole of the choke lever, as was mentioned earlier.

    Yes, you do need it, or any other device closing the choke valve in relation to cold engine temperature, unless you live in a very warm climate and/or do sunmmer driving only. Otherwise the cold engine will get too much air and too little fuel into the cylinders as fuel vapor will condensate on the cold intake runners, etc. Plus the choke thermostat spring also is in charge of raising the cold idle RPM, which is effected by the lever mechanism on the driver's side of the carb, actuated by the driver's side end of the choke shaft, which in turn, is moved by the choke thermostat spring.

    Aftermarket carbs often have electric chokes, which basically are the same spring (but mounted to the side of the carb itself) and also actuating the choke shaft via a tiny rod. These springs are heated up electrically when the igintion is turned on, whereas the original setup is mechanically reacting to the heat of the exhaust gas in the crossover of the intake manifold (so the original setup is somewhat more sensitive to actual engine temperature).
     
  18. Stoffauge

    Stoffauge Member

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    Alright that was the answer I was looking for . So it’s not on these picture because it’s more belonging to the intake manifold part of the fsm ? I am gonna get the one I posted earlier with the link . It’s for a 6125s I have from 71. it’s pricey but I want it original .

    thanks for the help .

    the wot is still present but gonna get the timing a bit more advanced and see how it’ll work out .
     
  19. ceebuddy

    ceebuddy Well-Known Member

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    Here is a link to a reproduction item, which is a couple of bucks cheaper. I have no clue if these are any good.
     
  20. 413

    413 Well-Known Member

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    Here is one from a 67-69 for an AVS. Compare to the Holley choke in post #9. Different rod. Similar flat mounting plate.

    Im Just showing this to compare to the 67-69 Holley choke in post #9.

    yes he needs the domed one. He has the correct on in his link in post #5
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    Last edited: Feb 19, 2021