AFB Issues? Choke Stove Pipe & Pulling

Discussion in 'Carter' started by Fragzem, May 8, 2009.

  1. Fragzem

    Fragzem Well-Known Member

    Hey guys, I'm not sure my stove pipe is doing anything for my choke. (Carter AFB).

    If I pull the end out of the exhaust manifold, should i be able to feel vacuuum or anything? How can I check this? Do these things frequently clog from carbon? I have a brand new one I bought from CARS it's only been on since December.


    anyway that's a small worry.


    My other problem is, upon acceleration the car will surge or pull back. It stumbles. Almost feels like a bad transmission, but I can tell the issue is in the engine.

    Feels like bad gas, also. But I've been through 3 tanks already and it's the same thing. It's usually more frquently-occuring when the engine is colder (first 5 minutes of driving) rather than warmer.

    It does not do this while the car is not moving. I can rev it beautifuly and it's smooth running with no problems.


    Time for a rebuild? Just got my tax return and I'm thinking I'll use some of that on having the carb done.. There's a local expert around my town who would do it for about $80. Doesn't have a shop or anything legitimate, but as soon as you mention the word "carburetor" in my town, this guy's name comes up.
     
  2. wkillgs

    wkillgs Gold Level Contributor

    Hesitation during acceleration could be caused by a lean mixture. A cold engine likes a richer mixture....It sounds like the choke needs to be a bit tighter. Loosen the black choke cover on the carb, and turn it a bit to increase the spring tension. Just an 1/8" or so. See if that helps!
    The choke should open up as the engine warms up...does it?
    I'm pretty sure there is a vacuum passage behind the choke coil. I'll have to check.
     
  3. 12lives

    12lives You die once. You live every day.

    On my 67 340 the pipe that goes into the exhaust manifold goes all the way through it and comes out the back. If you can pull it out it is broken. That's not unusual...they rust out and fatique at that point. I repaired mine with a sleeve and epxoy. If it is broke, the choke will never get warm and open all the way.
    - Bill
     
  4. 1BadWagon

    1BadWagon i got too many parts.....

    the tube off the carb slides into the tube in the manifold. this is normal to pull the tub out of the one in the manifold, it isnt normal if the tube in the manifold comes out. blow some air in the tube of the manifold and if it comes out the other side of the tube then it isnt plugged. if it doesnt then it may be time to pull the manifold and look inside it to see if the tube is damaged or rotted. its been a while since i worked on a carb with exhaust heated choke (i have electric on everything) so i cant remember if it will have vacuum at the line but i will find out for sure.:beers2:
     
  5. Fragzem

    Fragzem Well-Known Member

    Yeah that's all correct. the tube IN the manifold is fine. (does it go further than what meets the eye on the outside?) I'll try to blow some air and see what's up.. too bad my compressor took a crap a month ago. <grin>

    All I need is a 220 motor for this thing.. i wonder if anyone on the board might have one laying around.

    Anyway I just made a new post because I couldn't find this one.. (I was on the 2nd page and didnt realize it.. gimme a break its 8am and i haven't slept
    yet!! :Do No: )


    A spring came off here.... and I dont know what I did with it.. Do I need it? (Im sure) but its been runnin without it since November...

    http://img17.imageshack.us/img17/1209/1000700imw.jpg
     

    Attached Files:

  6. Fragzem

    Fragzem Well-Known Member

    Also wanted to add that this was an "Overnight" problem. Car was fine one day, next day this started.

    Going out to check the choke and stuff in a bit.
     
  7. doc

    doc Well-Known Member

    Frag, First , get some sleep , I used to work nights and can sympathize with you..... next, the nailhead engine has a ''divorced'' intake manifold and that makes the engine slower to warm up.... I have never had a nail that did not need 5 mins or so to warm up before they smoothed out and began to hit on all cyls... this is why the exhaust heat to the intake is important.... i would pull the carb off and ck the heat riser passages to make sure they are open and also the heat riser valve to make sure it works....both of these affect the warm up time.... even after warming up the manifold runs about 130 deg.... a lot cooler than the later bbb engines...
    If you have dirt daubers in your area , there is probably mud and bugs in the hole for the exh. manifold tube... just run a piece of stiff wire thru there to clear it out....be carefull around a car that has been stored, I found a copperhead and a bumble bee nest in my vehicles....
     
  8. Fragzem

    Fragzem Well-Known Member

    hey doc! thanks for jumping in here.

    I do let the car warm up, usually I start it and have a cigarette before I get in.. I should have specified that this hesitation happens all the time while driving, but it's worse when the car is cold. So I'm thinking.. warming up may not be the issue.. initially it might be, but 30 minutes of driving and this is still going on. If the doc says "CHECK WHAT I SAID ANYWAY".. then I'll go and do it.. :)

    Think I'll get off my lazy butt and play with the choke right now..

    -Pete

    whats the reccomended procedure to play with the mixture screws in the front?

    and doc, thanks for the bee's nest lookout hahaha but since I broke up with my last girlfriend, my Wildcat became my daily driver... <grin> so it's out there all the time, of course, I avoid rain 9 times out of 10 tho and snow always.

    Oh and one last edit::

    Where can I source linkage stuff? Particularly the spring that popped off what I believe is a secondary mechanism on the passenger side of the carb (shown in the pic above).
     
  9. doc

    doc Well-Known Member

    OOOOK, ck, the amount of gas ''squirt'' that you get when you snap the throttle open..... You may be getting a stumble and lean out backfire....that can happen if the accellerator pump is not working right....there should be a pretty good shot of fuel...to cover the sudden burst of air caused by snapping the throttle open....
     
  10. Fragzem

    Fragzem Well-Known Member

    hey doc.. actually just mingled with the air ratio today and it's running purrfect. about 1 1/8th turn on each side good rpm, much better idle than I've had in a while.. didn't know the information for tuning that stuff was gonna be in my Chilton.. but it was, so I did it.

    that being said, no lean-out backfires.. i can snap the throttle all day long, quick as i possibly can without issue...

    I wish I had an RPM gauge to say when this is occuring.. but I tried a brake stand today to see what happens, and right before the tires would break loose if you hold it there, with that load, it will stumble.. and stumble.. and then be fine for 3 seconds, and stumble, up until the tires break loose and its fine.. so i guess its just doing this under really heavy load. of course its still doing it upon WOT from a stop, it'll choke up right before second gear, and a bit thru it, and then fine after it gets into 3rd. (90% of the time).

    could it be too rich??
    I was going to change the oil, and the fuel filter in the carb, and the inline one today.. but my parts delivery guy doesn't stock Delco oil filters anymore (Fram and Wix only) so I'll do that tomorrow when I can go out and pick it all up at once.
     
  11. doc

    doc Well-Known Member

    If you will pm your ph. number, I will call you and we can transfer more info in 5 mins than in 2 hrs by posting....
     
  12. Fragzem

    Fragzem Well-Known Member

    Hahah.. doc.. I just thought of something plainly obvious.. and its almost embarrassing if this is what the problem is... Not going to say yet (so as not to look too stupid), but if it isn't the issue, I'll pm you a phone number tomorrow!
     
  13. Fragzem

    Fragzem Well-Known Member



    And... I think I just solved the problem. I'll drive it around tonight and keep you guys up to date.. Still don't want to reveal what it was just yet till I'm sure. lol

    -Pete


    any guesses tho??
     
  14. Fragzem

    Fragzem Well-Known Member

    MISFIRE.
    <grin>

    It's been so long since I've had a misfire on a 8cylinder pre-emissions vehicle i forgot they could even do that.. the system is so simple and straightforward!

    2 bad plug wires were arcing at high load causing my problem.. dammit

    anyway 90% of the bogging is gone. there's a slight issue that i can feel just barely upon acceleration, but i have a new distrib cap and coil here, i might as well replace those and check the plugs in the coming days..(i only put R44's in back in November) but hopefully it remains this simple!
     

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