Help with random shutoff.

Lincoln LS

  1. andreww9933

    andreww9933 LVC Member

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    Just recently my car has started doing something odd. When I come to a stop, it will randomly Rev high and then shut off. Normally it runs great, no rough idle or anything but sometimes when I go to slow down it fights me and maintains a fairly high rpm (usually around 1500 or so). I believe this is a faulty TPS sensor, but I wanted to get opinions and see if it might be something else.
     
  2. joegr

    joegr Dedicated LVC Member

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    For everyone else, this is a 1st gen V6.

    I'd put the IAC as a prime suspect, followed very closely by vacuum leaks (specifically the PCV valve elbow ).

    It should be easy enough to rule in or out the TPS, by watching it with a scan tool (even the free version of Torque). It should change smoothly while moving the gas pedal, and should be a consistent value with your foot off the gas.
     
  3. andreww9933

    andreww9933 LVC Member

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    It will Rev up smoothly when the gas is applied, but occasionally will stick when I release the gas. I also suspect a possible vacuum leak as you stated. What and where is the IAC?
     
  4. andreww9933

    andreww9933 LVC Member

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    Never mind, idle air control. That's actually brand new
     
  5. joegr

    joegr Dedicated LVC Member

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    The PCV elbow on the V6 is kind of famous for this sort of thing, though engine temperature is often a factor.
     
  6. andreww9933

    andreww9933 LVC Member

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    Where's the PCV elbow located? I'll check that out. Is it possible my throttle body could be a factor?
     
  7. joegr

    joegr Dedicated LVC Member

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    I believe that you have to remove the upper half of you intake manifold to get to it.
    Many things are possible...

    I haven't watched this, but it may help.
     
  8. andreww9933

    andreww9933 LVC Member

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    Okay. I'll look in to it more when I go on break and see what it says.
     
  9. andreww9933

    andreww9933 LVC Member

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    In the mean time, let me ask this. Would the PCV valve or elbow also cause a rough idle during cold temperatures? During winter when I'd start my car and the engine was cold it would idle pretty rough. It would drive fine though, and the idle would smooth out once the car warmed up.
     
  10. joegr

    joegr Dedicated LVC Member

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    It can. It's an unmetered air leak when it starts to fail.
     
  11. andreww9933

    andreww9933 LVC Member

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    Then I may go ahead and simply replace the PCV valve while I'm under there. It isn't exactly expensive and I'd rather go ahead and kill multiple birds whiten a single stone than have to tear in to it again.
     
  12. andreww9933

    andreww9933 LVC Member

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    Just wanted to say that KS for the advice on the PCV valve Between it and the egr pressure sensor (as Napa had it) my car is now fully functional and runs great! Engine light is now off and isn't returning any codes! Thanks a lot!
     

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