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Q-jet guru's, help???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Ben Malinski, Feb 13, 2003.

  1. Ben Malinski

    Ben Malinski Guest

    Q-jet guru\'s, help???

    84 blazer, electric choke, NO smog devices! (lucky to be in korea I suppose!) AIR, EGR, canisters, etc. GONE! Problem.
    When I start it up after sitting overnight, I tap the gas pedal a few times and it idles on high no problem. Once I kick it off fast idle, the lights dim, dash lights dim, etc. until I give it gas and drive off. Come to a stop and the lights dim again. This happens until it's completely warmed up then the lights don't dim. The alternator is new and checks out ok. I am thinking maybe the choke needs to be adjusted some more? What's your ideas? Again, once it's warmed up, the lights stay bright of course it idles fine, only when it's cold do I have this problem. Close or open the choke a bit more or another problem? Thanks!
     
  2. Dunc03

    Dunc03 1/2 ton status

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    Re: Q-jet guru\'s, help???

    is your engine bogging down when your lights are dimming. do you have to hit the gas after to initial cranking to make it go up on high idle. If this is the case it sounds like your choke is improperly adjusted. On some carbs there is a vacuum canister at the passenger side back of the carb. This canister opens the choke about an 1/8 of an inch when the engine starts. If the choke has to much tension on it this vacuum will not have enough vacuum ablied to it to force the choke open that little bit. The reason it kicks up on high idle after your rev it is becuase the higher rpm's create more vacuum thus giving the vacuum more power to open the choke a little. There is a more comprehensive post on this topic that was written to me about the same subject. This guy knows alot more about it and the other post explains it better. If you do a search for "Choke adjustment" you should be able to find a post by me Dunc03 and a reply by dyeager535(the name is not exact). It goes into detail on how to adjust the choke. WHen you do the search make sure that the criteria is set to all post, and not to the last week. Hopw this helps.
     
  3. wrathORC

    wrathORC 1/2 ton status

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    Hancock, MI
    Re: Q-jet guru\'s, help???

    What is the idle at? To keep it running do you have to keep a foot on the stupid pedal?

    You want the choke coming off all the way once it gets warm. It isn't going to like driving off until the gauge reads 150°. If the idle is too low all the time then bump up the idle with a screw on the driver's side. You get to the screw from the front of the carburetor. It's a chore to get in there with where the water neck is (and AC lines if you've got AC).
     

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