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TPS =17

Discussion in 'Gen 2 Prius Technical Discussion' started by douglas001001, Aug 15, 2007.

  1. douglas001001

    douglas001001 smug doug

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    Just curious if any of the technically knowledgeable or can-view'd people could verify what I think is happening in the following situation.

    When at highway speed and knowing I'm going to slow down I sometimes go to tps = 17, which leaves ICE on at idle rpm with scan gauge gph = .2 or .3. When I do this it seems like the gearing friction goes away and the car is coasting similar to putting a manual transmission into neutral and coasting with ice on.

    If this is the case, I think this might be a good alternative to warp-stealth when exiting freeways or for downhill segments immediately followed by P&g friendly terrain in cold weather when a ICE-off glide at higher speeds cools the cat to the point where forced ice on occurs following the glide.

    (one portion of my route is a long downhill to 4 miles of slow and go where I had forced ice on after gliding during the downhill in cold weather)
     
    #1 douglas001001, Aug 15, 2007
  2. hobbit

    hobbit Senior Member

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    The engine loses surprisingly little heat even during very long
    warp-stealth glides. Between the TPS you see and the full valve
    retardation, the net airflow through the engine seems to get reduced
    to almost nothing. Don't believe the GPH figure -- the ECU misreports
    that during fuel-cut states, or the OBDII device is doing improper
    math based purely on MAF figures. WS is a very low-friction state
    for the engine to be in, and the longer you can hold it the better
    overall you do.
    .
    _H*
     
    #2 hobbit, Aug 15, 2007
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    <div class='quotetop'>QUOTE(douglas001001 @ Aug 15 2007, 11:34 AM) [snapback]496199[/snapback]</div>
    Is "tps = 17" something displayed by an after market OBD scanner?

    Bob Wilson
     
    #3 bwilson4web, Aug 15, 2007
  4. JimboK

    JimboK One owner, low mileage

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    <div class='quotetop'>QUOTE(bwilson4web @ Aug 15 2007, 03:42 PM) [snapback]496330[/snapback]</div>
    Throttle Position Setting, displayed by ScanGauge.
     
    #4 JimboK, Aug 15, 2007
  5. David Beale

    David Beale Senior Member

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    I was quite amazed how narrow the "band-gap" was to get into "warp-stealth". Looking for really thin flexible sole shoes to make it easier to get there. ;) My Scangauge II also displays the same readings you got, though I haven't looked at the tps reading. Those with Can-view have confirmed there isn't actually any fuel being injected.
     
    #5 David Beale, Aug 15, 2007
  6. 1fixitman

    1fixitman Member

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    <div class='quotetop'>QUOTE(David Beale @ Aug 15 2007, 05:41 PM) [snapback]496419[/snapback]</div>
    I have been watching TPS on my SGII for a few days now mostly looking at what the best efficiency is for going up the hills I regularly travel too and from work as I think monitoring the 12V battery is.....well....boring.....so I decided to watch Throttle Position Sensor/Setting. I will look at what the TPS shows for all neutral stealth down hills that I do to see if it is 17 or not. I can tell you that without placing my foot on the pedal it is the number 11. I will keep a sharp look on my commutes (a whole 17 miles)
     
    #6 1fixitman, Aug 15, 2007
  7. ken1784

    ken1784 SuperMID designer

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    <div class='quotetop'>QUOTE(douglas001001 @ Aug 16 2007, 01:34 AM) [snapback]496199[/snapback]</div>
    Scangauge II displays incorrect data on such fuel cut mode.
    http://priuschat.com/index.php?showtopic=34275&st=1

    Ken@Japan
     
    #7 ken1784, Aug 15, 2007
  8. douglas001001

    douglas001001 smug doug

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    <div class='quotetop'>QUOTE(D Rock @ Aug 15 2007, 07:12 PM) [snapback]496531[/snapback]</div>
    ws (14/15), no arrow glide (14), ev assist in stealth mode ('harder' 14 and 15). 16 + will light the ice. 16 and 17 seem to be low/no fuel ice on coasting. The main inquiry for the post was to see if in 17 the gears are "freewheeling" and its like you're coasting in neutral.

    re David: if you are watching scan gauge trying to get into ws, let off completely until rpm hit 960 then reapply pressure. Once ice is off and is in battery spinning mode its much easier to get into the glide.

    re hobbit's answer: I'm not seeing engine temp go down, but a long ws glide at below freezing outside temps seems to put the car back in s1 like operation with ice on at all times, so I'm guessing it is cat converter temp too low. A couple of hard pulses usually get it back to normal so I was hoping that tps 17 was low gas flow enough to keep the cat warm while coasting in below freezing temps.
     
    #8 douglas001001, Aug 16, 2007
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