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idle adap

Discussion in 'L: Horizon/Omni, Rampage, etc' started by cadman777, Jun 15, 2016.

  1. cadman777

    cadman777 Active Member

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    Will someone please give me a link that explains what "idle adap" means, and how it relates to the other sensor numbers on a DRB II scanner?

    Thanx ... Chris
     
  2. cadman777

    cadman777 Active Member

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    Anybody wanna field this request, please?
     
  3. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    "idle adaptation at limit" - AIS motor is at its limit of travel trying to sustain an idle speed.
     
  4. ImperialCrown

    Level III Supporter

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    The EFI (TPS minimum idle speed) is an adaptive value. It is a 'fuzzy' logic that learns and controls base idle speed. Adaptives can get erased with a battery disconnect or manually selected and erased with the DRB.
    The throttle body minimum air adjustment screw is NOT an idle speed adjustment screw and shouldn't be messed with. There is a procedure at the dealer with a special tool and DRB used to get the adjustment correct. If the idle speed is too high or too low, there is another issue present. Do not touch this screw once set at the factory.
    The PCM watches idle speed RPM through the crank sensor and adjusts it up or down through the AIS.
    Idle adaptives that are at their limits or out-of-range are usually due to a vacuum leak (tries to slow down idle speed) or mechanical issue, etc (tries to raise up idle speed).
    The Powertrain Diagnostic Procedures book for what you are working on will explain adaptives and have DRB2 instructions. There was also a DRB2 user manual.
    The DRB2 has been pretty much obsolete since the 1994 when the DRB3 with a Supercard could take over DRB2 functions. Most shops no longer have anything old in the way of tools or paper manuals anymore. I see a DRB2 manual on ebay:
    CHRYSLER DRB II DRBII DIAGNOSTIC SCAN Miller TOOL C- 4805 Manual Instructions
     
  5. cadman777

    cadman777 Active Member

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    Thanx guys,

    Turned out that the EGR valve was bad. It was letting air into the system all the time. Took me 2 hours to run through every test in order to figure it out. As always, it was the LAST thing I looked at! What a waste of time ... anyways ...

    I already have a DRB II Diagnostics manual for this very model. Only thing is, the menu structure on my DRB II is not the same as what the book shows. Pretty sad.

    Instead of racking my brains to figure out if I'm following the lemming procedure in the book, now I just test components and circuits. Once I learned the basics, thanx to all the help I got in here (mostly), I do it w/a DVM, fuel pressure gauge, cylinder compression gauge, vacuum gauge, and scanner + CS (common sense). Learned the hard way that the 3 main problems usually are: 1. vacuum leaks, 2. connections, and 3. sensors. Can't believe the industry forced me to become an electrician!

    Incidentally, I just diagnosed a 98 Mercedes having a 'runnability' issue, w/o the aid of a diagnostics book. I used the same knowledge and CS I learned from you guys (and my books), and figured it out in about 2 hours. Not bad, eh?

    I remember the days when people would say it's wrong to shove your 'religion' down other people's throat. Well, the auto industry ignored that custom and has shoved their dang electronics down my mechanic's throat. Tastes bitter to say the least!

    Thanx again ...
     

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