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Q-jet problem

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by bigslok5, Sep 26, 2003.

  1. bigslok5

    bigslok5 Registered Member

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    Did some searching but didn't find any usefull info. So here's the deal. Idle seems to be fine but under a load the engine seem to hesitate.(sorda- glug, glug, glug) Checked all vacumme lines and did the cover the top of the carb trick. Seems not to be a leak. I think whatever is causing it is affecting my top end power as well. I also just changed the cap, rotor, and plugs and wires. (problem was before that)It has an HEI ignition swapped in. Saw something about the ignition wire having to be changed? Could this be affecting anything? I would think I could do over 70 with 3.73 gears and 31" tires. Something just don't seem right! Any help would be appreciated!
    Thanks /forums/images/graemlins/confused.gif
     
  2. bigslok5

    bigslok5 Registered Member

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    Need some Help!
    Let me know what you think! /forums/images/graemlins/1zhelp.gif
     
  3. JIMs70K25

    JIMs70K25 1/2 ton status

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    The biggest thing with the HEI would be if they did not run 12 volts to the coil and seperate 12 volts to the module i.e. used the wire that has the resisitve wire in it, this knocks the voltage down to about 8 volts, the HEI would not like that.
     
  4. Don

    Don 1/2 ton status

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    If the secondary "air valve" open's, too early, it will cause a big bog, [when it open's, it pull's the secondary metering rod's out of the jet's] causing to fat of a mixture. the engine simply cannot use that much fuel at a low rpm.

    Pick up the book, [Rochester Carburetor's]by Doug Roe, it has everything You'll need to know about Quad's, Mono's, and the electric Q jet.
     
  5. Ressurection

    Ressurection 1/2 ton status

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    One huge thing to check is if the throttle rods move in the throttle body. If so, you have air coming in through them, and the throttle body needs to be re-bushed. That was the prob w/ my Q-jet on my '72, and it took care of the problem immediately. E-mail me if you need more directed info! Good luck
     

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