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Secondary ports arent opening...

Discussion in 'The Garage' started by IL84JIMMY, Apr 19, 2004.

  1. IL84JIMMY

    IL84JIMMY Registered Member

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    I dont think that my secondary ports are opening when i floor it. What can i do to fix this? Or should i just invest in a new carb? I have the old quadrajet on there now. I am wondering if i can/should fix this or just replace it. /forums/images/graemlins/ears.gif
     
  2. R72K5

    R72K5 Banned

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    it is adjustable, the secondary flaps anyways, it is spring loaded tight shut the engine vacuum, is what makes them open up, when air is getting sucked through carb at higher rpm, they basically get sucked open, up under neath the spring loaded end of the secondaries flappers shaft is a torx head lock screw loosen it up and then trn the shaft screw whichever direction that lessens the spring load that keep sthe flappers shut, IE lessen the resistance, this will make the flappers open alot easier and sooner.,

    play around with the setting until it opens at the acceleration ledal height you want it to, or at the RPM you want it to,


    dont throw away a compelte Q jet, even if needs rebuild, i plan on buying up complete and rebuildable Q jets of all years onc ei am back at work, so i can rebuild and test and sell them some day i have great luck with them with a rebuild kit /forums/images/graemlins/laugh.gif


    good luck
     
  3. sled_dog

    sled_dog 1 ton status

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    I would invest in a new carb. I had the same problem. Fixed it by eliminating the vaccum stuff on the carb, but it still ran like junk. Replaced it with a new Edelbrock, never will look back.
     
  4. RaisedK5

    RaisedK5 1/2 ton status

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    Is the secondary lock-out unlocking the secondaries?? if the choke rod and or all that crap on the pasenger side of the carb is out of whack, the secondaries may not be unlocking.
     
  5. Rustheap

    Rustheap Registered Member

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    I would suggest learning how to tune it before you throw money at a problem like that. There are several great articles on this subject and they cost little to nothing! Start with this one. /forums/images/graemlins/burb.gif
     
  6. Blazer1970

    Blazer1970 1/2 ton status

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    How do you know the secondaries are not opening? The secondaries on a Q-Jet will never open unless the engine is under load (and the choke is all the way open as mentioned above). You can not get them to open by revving the engine in the driveway.
     
  7. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    [ QUOTE ]
    How do you know the secondaries are not opening? The secondaries on a Q-Jet will never open unless the engine is under load (and the choke is all the way open as mentioned above). You can not get them to open by revving the engine in the driveway.

    [/ QUOTE ]

    I agree 100%. Make sure when it's fully hot that the base plate butterflies are opening at full throttle (I have found short down shift cables incorrectly installed on TH350's that prevented this) and leave it alone till you know what your doing. It's probably working just fine. More people screw up messing with that tension spring on the top doors and then make their QuadraJet a Quadrabog.
     
  8. R72K5

    R72K5 Banned

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    well i assumed that he already knew that his throttle plates were opening but you are right he has to make sure they are opening up and not locked out first,

    form what i can tell the carb works fine but he just isnt haveing secondraries opening up and working, in which is no where near a good enough reason to toss a carb and waste money on a new one,

    carbs are easy to work on, the only way to learn how to work on them is to study them and work on them, just like anything else like engines, trannies, etc.


    ppl are telling him to replacew his carb and are just assuming that the carb is junk, and i have a feeling that ppl who are doing such just dont personally like Q jets and dont know how to work on them and properly tune them in and such


    good luck
     

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