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Thread: Engine Bogg after FMIC install

  1. #1
    Join Date
    Apr 2008
    Location
    Vallejo, CA
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    59

    Engine Bogg after FMIC install

    After installing the FMIC I am having and issue when giving moderate to heavy throttle the engine chokes out from a idle, and low speed acceleration. The piping runs out of the blower down between the engine/radiator, around the front, then connects into the intake side (a lot of piping). Sooo, I'm pretty sure when the bypass valve shuts the engine is robbed of air due to how long the air has to travel. No other issues besides this, and it did not do this with the stock set up. Has anyone experienced this, and come up with a solution? The only thing I can think of to fix this is to some how limit the bypass valve from closing so quickly.

    Douglass

  2. #2
    Join Date
    Jul 2004
    Location
    Hamilton NJ
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    2,051

    Major vacuum leak

    Sounds like a vacuum leak, the bypass stays open til you floor it and boost kicks in and closes the bypass, its suppose to close during boost. If its closing during idle I would say that the bypass valve is bad, but it would still run.
    Check your vac/boost guage at idle it should be around 17-20 vac
    Last edited by 89XR7TD; 06-08-2018 at 06:54 AM.
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  3. #3
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    Sounds like a vacuum leak to me too or it needs a retune or something changed with the fueling.
    ~Chris
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  4. #4
    Join Date
    Apr 2008
    Location
    Vallejo, CA
    Posts
    59
    I think I may have described it wrong. Lets say I am idling, Looking at the engine and giving gas to the throttle body by hand. Scenario one: If I ease into the throttle, then go WOT it is fine. I can see the bypass valve working. Scenario two: From idle, if I go WOT I can see the Bypass valve close instantly, stay closed, and the engine boggs down (almost sounds like shutting off the engine).

    Vacuum at idle is good, and Boost is solid 10-11psi.

  5. #5
    Join Date
    Dec 2007
    Location
    Pacific Rim
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    Trying to imagine how you can have boost and it falls flat at the same time...

    About scenario 2 - when you do that, can you see all the rubber couplers to confirm none have collapsed/split/blown off?

    Any photos of the plumbing you can share?

  6. #6
    Join Date
    Apr 2008
    Location
    Vallejo, CA
    Posts
    59
    Trying to imagine how you can have boost and it falls flat at the same time...
    Good Point, I'll see what the boost/fuel ratio is when it happens.

    About scenario 2 - when you do that, can you see all the rubber couplers to confirm none have collapsed/split/blown off?
    From what I can see everything looks good, and seems to be operating correctly on the valve

    Any photos of the plumbing you can share?
    Here is the best picture I have at the moment. The piping wraps around the front continues around the left side, then back into the factory inter-cooler pipe.

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    Last edited by burzum10; 06-08-2018 at 01:57 PM.

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