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Thread: High idle, only in drive?!

  1. #1
    Tuning Addict blindsquirrel's Avatar
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    High idle, only in drive?!

    2006 E40, stock everything except the tune file and MAF is deleted. Idle airflow tables are completely untouched. Stock clean throttle body. No vacuum leaks. I have tried the scanner's 'throttle cleaned' and Tech2's 'idle relearn' to no effect, they both seem to do nothing.

    This is melting my brain. Idle in park is good, actual RPM is within 30-40 of Idle Desired RPM, Throttle Position and Throttle Desired position are ~2.4% after it stabilizes after startup. Reverse is within 30-40 RPM of desired, Position & Desired are ~4.5%. Neutral same as park. But in drive and only in drive, Throttle Position & Throttle Desired jumps to 8%, with Desired = 552, actual = 725. Back to neutral, reverse, & park it behaves normally. I cannot find anything anywhere in the tune file that would account for this. It's not spark related, something is telling the throttle blade to open, only in drive.

    Of course, when driving, coming to a stop it's trying to push through the brakes and engine speed flares at the 2-1 downshift, etc. How do I fix this?

    Short log of start, reverse, neutral, DRIVE!!!!!!!!!1, neutral, reverse, park: 21-02-28 21-50-43.hpl
    Mess of a tune file: 2021-02-28.hpt

  2. #2
    Senior Tuner
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    I had this same issue on a P59 application a few months ago. It was very odd. The only way I was able to fix it was to remove airflow from the Min airflow tables in the forward gears and reverse.

    Try this and see if it helps you with the first startup and with the idle issue as well.

    2021-02-28 KW Mod.hpt

  3. #3
    Tuning Addict blindsquirrel's Avatar
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    Heh, you noticed the crank-chug-die just from that logfile? That's literally the one and only time it's done that in the two years I've owned it, and of course it happened to be during the log I was making only for the purpose of posting it here... lol.

    Huge difference. It's within ~20 RPM of Desired now, in D. 21-02-28 23-09-11.hpl

    Any idea what caused this? I'm sure I would have noticed if it'd been like this all along, though I can't pin down exactly when it started.

  4. #4
    Tuning Addict blindsquirrel's Avatar
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    And I double checked, nobody drilled a hole in the throttle blade while I wasn't looking.

  5. #5
    Advanced Tuner
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    You check trans fluid level? Low fluid can cause idle to flare up.

  6. #6
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    I have a similar issue with a 2006 E40. Stock motor with D1SC and id1050. (Did the same with Siemens 60s.) No holes in my TB...

    Idle is set to 550 but the only time it will idle below 650 is when I am coasting at ~1-3mph. Jumps back to 650 once stopped. Used all stock idle, idle airflow, and idle spark information. Once I set the VSS idle to 650 it will stay at 650 when coasting ~1-3mph. Scanner commands will not lower the idle below 650 either.

    I feel as if there is another idle setting or two not shown in the editor but have not found anything in my search yet.

  7. #7
    Tuning Addict blindsquirrel's Avatar
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    All fluid levels present and correct, Sir. But since you mentioned it, how/why would that cause the ECM to open the throttle blade to 4-5% in reverse, and 8-9% in drive? I mean, to confirm what I was feeling I went and found a wide open flat level parking lot, released the brake, and without touching the throttle this thing would take off and accelerate, make the 1-2 shift and maintain 18 MPH just like the cruise was set.

    It looks like kevin just whacked 20% out of ECM 12807 and mostly cured it; it still would not ever go below the target idle speed, it was still never less than 20-30 over. I removed another 5% from that and it's now occasionally dipping slightly below the target idle at times.

    eXo: This is the table you need to tweak.

    screenshot.04-03-2021 13.23.57.png

  8. #8
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    Only other thing that came to mind was maybe the TFP not agreeing with the PRNDL and making it fail to ramp out garage shift torque. That's more of a guess though, not even sure which 60e's had the TFP and which didn't.

  9. #9
    Tuning Addict blindsquirrel's Avatar
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    Oh, it responded to gear position all right, too much. It ramped IN torque, only in drive. A/C on/off also didn't make it better or worse.

    It's just occurred to me, being a former dealership tech. What the fuck would I have done, in a dealership setting, if a truck with this issue had showed up in my bay and I had no tools to fix it other than a Tech2 and the parts counter? (and also being paid flat rate)

  10. #10
    Tuning Addict blindsquirrel's Avatar
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    Trans Pressure Mode PID is working in my logs, shows Garage Shift and Steady State and Shift when it should. This is a 15-pin 60E, definitely has the TFP.