Thermoquad question

Engines, Exhaust and Fuel Systems

  1. Davesmopar

    Davesmopar Well-Known Member

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    Need help with choke pull off linkage.....

    Does it go like this one??? 20191017_1234335858588335959031790512367883.jpg



    Or this one???
    20191017_1233525858582724219393950347796879.jpg
     
  2. AJ/FormS

    AJ/FormS Well-Known Member

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    I see the same pic posted twice and neither is right,lol.
    I haven't worked on one for over 20 years but I'm pretty sure that lil arm in the foreground is supposed to be below the pull-off stump, so that when the vacuum comes up, after the start, and as the engine cleans itself out; the pull-off, pulls down on that arm; which IIRC moves the fast-idle link, so that when you tickle the gaspedal, the fast idle cam falls to a lower step. Make sense?
     
    Last edited: Oct 17, 2019
  3. Camtron

    Camtron Well-Known Member

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    Repair Guides

    Surprisingly clear adjustment procedures; from Autozone of all places lol
     
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  4. Davesmopar

    Davesmopar Well-Known Member

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    Thanks guys.....

    Ty for the link.....
     
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  5. Camtron

    Camtron Well-Known Member

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    No problem. I’ve only messed with the Holley/street demon thermoquad look a likes with electric chokes...nice little carbs
     
  6. Davesmopar

    Davesmopar Well-Known Member

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    Hey BudW, do you have information on the thermoquad you could post oh, I've have a basic setup but I need fine-tuning
     
  7. BudW

    BudW Moderator Staff Member

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    Been a bit behind on forum reading and just now read this. I will try to go into my deep freeze (aka, my detached garage) and take some pictures, tonight.

    What is the TQ model number you currently have (example is 9123s).
    BudW
     
  8. M_Body_Coupe

    M_Body_Coupe Well-Known Member

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    I've got the original Carter Service Manual, 32 pages of best TQ info you'll find anywhere...problem is, total size: 32Meg...LOL, yeah, way too big for what our site can handle.

    Can anyone suggest a way to place this anyways? Do we actually have a Tech Library section where we could upload things?
     
  9. Davesmopar

    Davesmopar Well-Known Member

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    9023S. So 9023.....

    I really need to know how to set the metering rods up, I can't find anything on the interweb. That maybe my off idle stumble
     
  10. Davesmopar

    Davesmopar Well-Known Member

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    Do you think you could email me the files thank you
     
  11. 89.Fifth

    89.Fifth Well-Known Member

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    I've been thinking about this too. I want to create an FMJ tech database but I have so little time to work on projects like that.

    I can create a DropBox link that holds everything for now.

    If there are any files you want to see uploaded please send me a message and we can figure out how to do that.
     
  12. Camtron

    Camtron Well-Known Member

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    If you can take clear pictures of the pages with your phone, you can start a thread and post the photos of the pages. I think you can post 10 photos per comment/reply so, it’d take 4 comments/reply’s for you to upload all the photos
     
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  13. Camtron

    Camtron Well-Known Member

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    Do you get fuel out of the accelerator pump as soon as you move the throttle, is there any slop/slack in the accelerator pump linkage? New ethanol cut fuel likes a fatter primary jet, may just need to step up one or two sizes. If you take your finger, can you push the secondary air door open with your finger while the engines running? You shouldn’t be able to push it open at all without immediately fighting against the secondary pulloff. If you have a mild built engine, you may need to drill the accelerator pump nozzle ids to .031" to get a bigger fuel shot
     
  14. 89.Fifth

    89.Fifth Well-Known Member

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  15. AJ/FormS

    AJ/FormS Well-Known Member

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    Off idle stumble is almost always one or, or a combination of, the following items.
    1) fuel level ,
    2) ignition timing
    3) transfer slot synchronization/ ignition timing,
    3b) throttle valve synchronization
    4) Accelerator pump shot,
    5)PCV or vacuum leaks

    Check these first before you start messing with the metering rods.
    Check/adjust them in the order listed.
    If not a stock engine,post up what you got, but
    for a stocker or near stock (no cam);.
    1) The correct fuel level establishes the ease of fuel pullover,but
    The further your transfer slots are from ideal, the less a fuel level correction will affect a change, unless it's really out to lunch. Always always start with an accurate fuel level.On the chance that you have already done this, you can skip over this for now; and do the rest first, it's just easier. If we still have a problem later, then we can come back to this at that time.
    2) Set the timing back to stock.If you have a buncha vacuum controlled devices, those all have to be working and plumbed. We can talk about those later. Right now, your carb is calibrated for all those devices to be working, and if they are not, then you will be fiddle-farting around until you accidentally hit the magic combo, or forever if you don't..
    3) The transfers are your basic low speed circuit. But if your timing is out of spec then the transfer slots will be too; you cannot arbitrarily crank up the timing because somebody told you to. So, here's how to set those;
    Take the carb off, make sure the throttle valves are not on the fast idle cam. Make sure they are on the curb-idle screw.Then flip it upside down and Now is the time to check 3b.
    Unscrew the curb-idle speed screw until the throttle valves are BOTH touching the throttle bores and they are simultaneously both sealing the bores. If this does not happen, then it is because either; the throttle shaft bushings are worn or, one or both throttle valves are bent or, one or both is not centered on the shaft, or the secondary link is too tight. Find and fix the problem before continuing.
    Ok now,go find the Transfer-slots in the primary bores.Start on the drivers side cuz, IIRC that side has only the one vertical slot. Now go to the passenger side and find the matching one.
    Now with the throttles closed, but not jammed closed, using the curb-idle screw, adjust the transfer slot exposure,with the carb still upside down, until the slot is a tiny bit taller than it is wide. Just enough taller that you don't have to squint to see it. Double check that what you did,matches what I typed. From now on, leave that speed screw alone!. you will be using timing to set the idle speed
    Ok now, figure out how to make this adjustment with the carb NOT upside down, cuz I can almost guarantee that you are gonna want to turn the speed screw, and if you do, then you just screwed up a half an hour. And I will not be happy!lol. The usual method is toback off the speed screw,counting the number of turns it takes to fully close the throttles but not lift the screw off the adjusting lug. Right it Down, dogone it. Then put it back to where you found it.
    One more thing; make sure the secondaries close up tight at the new curb-idle screw setting; tightly closed but not sticking.... both of them the same.
    Now reset the low-speed mixture screws to 2.0 turns. These are NOT your low-speed fuel system; they are just idle trimmers. Do not try use them to idle your engine on, cuz I GUARANTEE that will cause trouble; they are just trimmers.
    4) every time you change the idle speed, you will/may have to reset the Accelerator pump starting point. This circuit on a Holley has to be functioning perfectly. But on a TQ, if you get the basics set right on a mechanically sound engine, then it can be a little off base and you might never know it. Which is good cuz sometimes on TQs this circuit is a PITA to get working right. The bottom line is yes, the pump should deliver fuel at the slightest tickling of the throttle valves, and it should be a spray not a dribble or a frothy dribble. You may have to stroke it several times to prime the circuit. But wait until there's fuel in the bowls!,lol, to check this.
    5) Make sure you got a good working PCV, and no vacuum leaks. How can you know about the PCV? I don't know either, for $5.00 i just get a new correct for the application one, make sure it rattles when I shake it,and shuts off when I blow into it,then stick it on there. It will be fine.
    >Ok after you get all this done, you can reinstall it, prime it, fire it up, and warm the engine up. Do not touch the curb-idle screw! If she won't stay running, put her up on the fast idle cam, until she's warm and happy.
    After she's warmed up, kick her off the fast idle.
    If she stalls;
    Do not adjust the curb idle screw! Put a vacuum gauge on the intake manifold, pull some timing in, just tug on the D and rotate her about a half inch, right now it don't matter how much, we just want a running engine. Ok fire it up.
    If she's running faster than 750, retard the timing until it gets down to there, still on the curb-idle screw.Then check the idle vacuum.
    Still on a stock engine, I'm looking for 15 inches at 750rpm, or more.
    If you're there, and this is an automatic car; then, have a helper step on the brake and put her into gear, then check the vacuum and the rpm. If the engine is happy, then retard the timing until you see 600/650 with a happy engine. Finally still in gear, adjust the mixture screws, both the same, up to 1 turn either way, to make the engine as happy as she can be.
    Now if the vacuum falls below .......... I'll guess 12 inches while doing this; or if the engine won't idle at 650 in gear; then STOP! something is wrong. Now put it back into park. And we can talk about that in another post.
    But if it took thatchit, then, put a timing light on it and let's see where she's at.
     
    Last edited: Nov 19, 2019
  16. Davesmopar

    Davesmopar Well-Known Member

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    Okay guys I'm about to beat my head on the wall here, let's just say the carburetors professionally built and I being a dumbass went and messed with the metering Rod okay. Now how do I set the primary adjustment set up on the metering rods that's all I'm asking. I've got it tune to where they broke the Tire loose between 30 and 40 miles an hour on a Stomp.......


    I greatly appreciate everybody's help but I cannot find anything unless I'm missing it about the static set up on metering rods, the owners manual say Do not mess with it, well guess what I done freaking messed with it so now I need to put it back to oem specs so I can start adjustment and fine-tuning it.....

    Again thanks for everyone's advice......


    I've got 9 1/2 to 1 forged flat tops, stock 340 cam J heads that have been ported polished 80% of the valves, and the intake is a Factory 340 that has been ported and Polished to match the heads.. long tube headers wirh 2 1/2,inch exhaust
     
  17. Camtron

    Camtron Well-Known Member

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    I’m not sure I fully understand. What did you do to the metering rods? Change them to a bigger/smaller size or to a stiffer softer spring? Or are you talking about the adjustment screw?
    Depress the metering rod primary piston until it lightly bottoms in the bore. Hold it there. With a small screwdriver, turn the screw counter clockwise until the primary piston stops going down. Then, slowly turn the screw clockwise taking note where the primary piston starts to move up. From the point it begins to move up, turn the screw 1 1/2 turns clockwise. This is a starting point. From there you can fine tune it by turning the screw clockwise to richen the mixture and counter clockwise to lean it.
     
  18. Davesmopar

    Davesmopar Well-Known Member

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    I turned the adjusting center screw..... but it does have the 3 step rods versus the 2 step rods installed years ago......

    Now that is with the choke off throttle blades closed correct?......

    Thanks again......
     
  19. AJ/FormS

    AJ/FormS Well-Known Member

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    Start it up, warm it up, set the mixture screws to 2 turns out. Set the timing to 8 degrees., put the rpm up to 2200 rpm .
    Now drop the metering rods down into the jets until the engine complains about it, then back up a half turn;... or if you have an AFR gauge, until you hit about 15.0
    Then put the rpm back down and go for a ride.
    That's the best I got.
     
  20. Camtron

    Camtron Well-Known Member

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    Correct