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Thread: TBI conversion bogs bad when cold, log included

  1. #1
    Carb and Points!
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    Oct 2013
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    5

    TBI conversion bogs bad when cold, log included

    Normally I don't stab the throttle when the engine is cold but I noticed when I do, it almost stalls. Eventually, it coughs and sputters until rpm gets up a bit and then it runs. Gradual throttle to the floor does not cause any major issues.

    AMC 258, manual trans, no egr or knock, no vss.

    I attached a short log to duplicate the bogging issue and an earlier log with a lot more data.

    I would appreciate any feedback I can get.

    Thanks!
    Attached Files Attached Files

  2. #2
    Fuel Injected!
    Join Date
    Sep 2013
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    Tulsa, Ok
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    Without looking at the logs, a bog is usually cause by a lack of fuel. You did not mention the ecm youre using so its hard to say what parameters you need to look at.

    Buddrow
    If it don't fit force it, if it don't force fit f&%@ it!

  3. #3
    Carb and Points!
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    Oct 2013
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    '7747 ASDU tuned by others.

    I had a slight vacuum leak at the intake, I tightened all of the bolts, reset the idle to 450 and reset the IAC.

    It was idling at 600-650 and I went out to run another log, now it idles at 750?

    No error codes.
    Attached Files Attached Files

  4. #4
    Fuel Injected!
    Join Date
    Sep 2013
    Location
    Tulsa, Ok
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    Id look at the ve tables first. Could be a fuel pressure problem as well i.e. Fuel pressure low. Im not near my laptop or Id have a look at ur logs. What are the BLM's?
    If it don't fit force it, if it don't force fit f&%@ it!

  5. #5
    Carb and Points!
    Join Date
    Oct 2013
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    5
    I have 15 psi supply and 1 psi return.

    BLM from second log.

    And thanks for helping out, I am decent with computers, good with firearms and designing buildings...but suck at '7747 logic.


  6. #6
    Fuel Injected!
    Join Date
    Feb 2013
    Location
    Euless, TX
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    2,308
    Being that the truck is an I6, it probably needs more TPS & MAP AE to compensate for the longer intake manifold.

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