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Scrap the TBI and go carb??

Discussion in 'The Garage' started by js4x4, Nov 9, 2004.

  1. js4x4

    js4x4 1/2 ton status

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    I have a DD, with a 305. the dang thing never wants to idle at stop lights...its an electronics problem i can't seem to figure out-all the sensors and crap are now NEW. (wasn't throwing any codes) I disconnect the wire to set timing-and it idles great( idrove it disconnected-great except when i get the RPMs a lil high it doesn't advance, so sputters)...connected cough sputter sputter...die. I am lead to believe its a timing issue, but the computer is leaning it out i think. I am thinking of eliminating the computer altogether and going carb. Someone posted info on a 300HP+ 305 building the top end only, and its very tempting, and that set up had a carb.....any thoughts on this??
     
  2. Pookster

    Pookster 1/2 ton status

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    A finely tuned carb is very nice. However, To create a finely tuned carb is very difficult- in some ways a lot more difficult. I couldnt do it if my life depended on it.

    TBI isnt that different from a carb, but if it wont idle at stop lights-, it oculd be one of several things, including transmission. Even if the sensors are new, it doesnt mean that the computer is recognizing it, or worse yet, it could be that the computer is reading it wrong.

    get a scanner and check the air fuel
     
  3. loafer

    loafer 1/2 ton status

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    Personally, I wouldn't do it. I converted my 86 from a carb to TBI because the carb sucked on steep hill cimbs.

    Did you check/replace the ESC module? The module is expensive, so I would try to borrow one out of a buddies truck to see if it's the problem. Make sure you try one out of a 305 not a 350 though.

    If you have already checked the ESC then try swaping in an ECU from another truck. They're easy and dirt cheap to find at junk yards.
     
  4. Emmettology 101

    Emmettology 101 3/4 ton status

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    Check for a vacuum leak or a vacuum line that is not connected up. My 89 3/4 was idling rough and dieing at lights and I had a vacuum line come off the back of the TB..
     
  5. loafer

    loafer 1/2 ton status

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    [ QUOTE ]
    Check for a vacuum leak or a vacuum line that is not connected up. My 89 3/4 was idling rough and dieing at lights and I had a vacuum line come off the back of the TB..

    [/ QUOTE ]

    Yeah...damn good thought.

    Which reminds me; The gasket between the TBI and the intake manifold commonly fails on thes units and will cause a huge vaccum leak. Easy and cheap to change.
     
  6. Emmettology 101

    Emmettology 101 3/4 ton status

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    [ QUOTE ]


    Which reminds me; The gasket between the TBI and the intake manifold commonly fails on thes units and will cause a huge vaccum leak. Easy and cheap to change.

    [/ QUOTE ]
    I've had that happen before also. But usually the first sign of that happening is the idle going way up...
     

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