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Thread: truck keeps giving fuel after I lift the throttle

  1. #1
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    truck keeps giving fuel after I lift the throttle

    I am having an issue with when I floor the truck and let off it keeps on fueling. It is a gradual slope down after I lift until it gets down to 0 mm3. I tried messing with the main droop and alt. droop settings. I tried raising the values up to like 40 mm3 at 4000 rpm, with the thought that it would be able to take fuel away quicker after I lift but that just made the truck extremely slow. Full throttle barely gave it any fuel. So I put it back down to the setting I have in the tune below and it feels good, but it is a kind of unnerving feeling when you let of the throttle and it keeps on going for a second. Does anyone know what would be causing this or what the droop tables are used for. Thankschananged droop seetings back to 10.20.hpt

  2. #2
    Senior Tuner Jim P's Avatar
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    Droop settings is part of PID control for regulating the governor it?s tied with.

  3. #3
    Senior Tuner Jim P's Avatar
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    http://www.woodward.com/-/media/publ...6/55/01302.pdf

    This is more geared towards generator speed control application but it?ll give you the bare basics on its theory.

  4. #4
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    ok, I kind of get it. So when I put higher values in the table it must just be starting to enable the governor way early? maybe. Do you know what I could mess with to have it return fuel back to just like the minimum fuel to idle after I floor it and let off the throttle? I was looking at my log and after I lifted it is a straight slope down from like the 2700 us to 0 but it took it around 3 seconds to do so. thanks

  5. #5
    Senior Tuner Jim P's Avatar
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    I haven?t looked at your tune or anything but sometimes it can be from rail pressure hanging high.

  6. #6
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    Try changing the deceleration limit in the governors tab. I had this on my manual 06 so I set the rate select rpm to 8000 to keep it from coming on and it seemed to work. I cant log it tho. I was going to pull this tune back over to EFILive to verify.

  7. #7
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    awesome that seems like what is probably going on. I just didn't see that table before. Im gonna try it out then I let you know if that fixes it. thanks

  8. #8
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    thanks arin, that did it!! It took the fuel out way quicker than before.

  9. #9
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    Good! This specific issue was one of the reasons I bought HP Tuners.

  10. #10
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    what all did you change in the decel limits to change that??
    looking to fix a similar issue in my 03 manual

  11. #11
    Tuner MAIDENCR's Avatar
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    No throttle fuelling table
    Work wonderfull on my 03
    03 cummins,250hp nozzle,dual cp3,s467.7/83 1.00
    Nv5600 with valair triple disc clutch

  12. #12
    Tuner MAIDENCR's Avatar
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    You got fixed???
    03 cummins,250hp nozzle,dual cp3,s467.7/83 1.00
    Nv5600 with valair triple disc clutch

  13. #13
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    This worked for me when I was running just HPt but changing to EFILive CSP5 I think it got blown away during the conversion. Now I am just pulling all timing out and that works tooScreenshot 2020-11-03 220837.png

  14. #14
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    What I found worked good was using the part throttle governor table. I would put a low limit in there at lower tps and it would pull fuel out right away.