Holley electric choke - pull-off adjustment

Discussion in 'Engine Topic' started by jamieg285, Mar 6, 2009.

  1. jamieg285

    jamieg285 Veteran Member

    1,224
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    Jul 15, 2004
    Luton, England
    Can anyone give instructions on how to adjust the choke pull-off on a Holley electric choke?

    I have established that my hard starting problem is most likely caused by this being wrong, but I haven't been able to find any decent instructions on how to adjust it. I have a later model choke, where the adjustment is with an external screw, not a bendable tab inside the housing.
     
  2. ZS10

    ZS10 Moderator Staff Member Lifetime Gold Member

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    Jan 18, 2003
    BC, Canada
  3. Stroked72SS

    Stroked72SS Veteran Member Lifetime Gold Member

    322
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    Oct 26, 2005
    Bryan, Texas
    I always "Pull them off" and throw them away...With the Carb adjusted right, a choke isn't needed
     
  4. jamieg285

    jamieg285 Veteran Member

    1,224
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    Jul 15, 2004
    Luton, England
    Anyone know?

    Neither of these suggestions will help me.
     
  5. phbmd

    phbmd Veteran Member

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    Feb 11, 2008
    Olney, MD
    Jamie,

    The Holley Website has literature for rebuilds, choke kits, and has carb. owners manuals. They also have techs available by phone - I have called a couple times for help after rebuilding my 4160 and changing to electric choke.

    My electric choke had only two adjustments. You adjusted the fast idle speed when the high lobe on the fast idle cam contacted the adjustment screw. You also adjusted the chock duration by loosening the three screws on the housing and turning the black cover. Winter is just ending in D.C. and the choke seemed to do it's job pretty well after those two adjustments were made (started right up in the cold and ran at 1400 rpm - and I could kick it down after only a minute or so).

    I guess you can be a total radical : ) and have the choke close minimally but adjust the fast idle speed on whatever cam lobe the screw is contacting at that point. But the standard adjustment method worked in my case.
     
  6. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    Sep 20, 2004
    Southern Maryland
    If your car will run fine cold with no choke, it's set up too rich.

    I didn't think the Holley had a "pull off" (like the vacuum break that Qjets use, when the car first starts, it opens the choke flap a preset amount, that is adjustable)
     
  7. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    8,191
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    Jun 22, 2003
    Endicott, NY
    Any "automatic" choke is adjusted in this manner: loosen the screws (usually three of them) to that you can rotate the cap where the bi-metal is. The engine should be cold (you can also use a cooling agent like ice to cool the thermostat down), adjust the choke mechanism so that it is just closed by turning the cap on the choke. I've used this method before and it is usually close to what the engine needs for a choke adjustment. The only variable in this is the outside temperature. If it's VERY cold outside, you may have to back off on the closed adjustment a little. Conversely, if it is VERY hot out, it should be OK the way you adjusted it but you may have to back it off a little to compensate for cold weather. After all, the idea is to have it open as the engine warms up, not to stay closed forever!
     
  8. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    Sep 20, 2004
    Southern Maryland
    the problem is that without a vacuum break for the choke, like a qjet has, on some applications with a bimetal choke actuator, in order to get enough choke "on time" by turning up the preload on the spring, the choke plate will then end up so far shut, that the car will load up and run way overrich for the first few minutes until the choke starts to open. Edelbrocks have a spring loaded plunger in the choke flap, to semi-remedy this, but the Qjet choke pull off is the best electric choke setup ever used.
     
  9. Stroked72SS

    Stroked72SS Veteran Member Lifetime Gold Member

    322
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    Oct 26, 2005
    Bryan, Texas
    That's not what my Wideband says...
     
  10. jamieg285

    jamieg285 Veteran Member

    1,224
    2
    Jul 15, 2004
    Luton, England
    Wow, a flurry of activity, but sadly still no answer.

    I understand how everything is supposed to work. The block cover controls how quickly the choke opens, not how it reacts on immediate startup. The fast idle cam again, controls the idle speed in relation to the choke position. Neither of these are the problem.

    The problem I have is on immediate fire up, the choke should open a fraction from fully closed, under the influence of the increase in vacuum. This is known as the pull-off, and should be adjustable, controling how much the flap will open at this time - totally independant of the black cap or fast idle settings.

    There are some instructions in the Holley documentation, but it is only for the older style, where you adjust a tab inside the housing. I have a newer one, and there isn't a tab to bend, just a screw. I don't know if this screw is the adjuster, or is a lock screw, or even something else. I don't know how to adjust the thing to get it to the right setting (which, for initial setting) is going to be 1/4 from fully closed.

    I've emailed Holley, but had no response yet, so may call them later today, but still hope that someone may have the answer anyway.
     

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