2003 Mack E7 power issues

Discussion in 'Mack Forum' started by niceguypmp3, Aug 12, 2018.

  1. niceguypmp3

    niceguypmp3 Bobtail Member

    43
    8
    Aug 31, 2009
    Weldon, IA
    0
    On the 2003 Mack with a 350hp E7 and allison auto tranny that we just purchased a few days ago, i noticed driving it home that when pulling hills, then sometimes when you put the pedal down to pull the hill then the turbo spools up but then sometimes after 5 seconds or so then it will spool up even more and it has quite a bit more pulling power even though the tach doesn't move. It does it with the cruise on and also with it off so i don't see how it could be the pedal sensor. Could this be what they call a dual HP engine? Why would it be doing this? It didn't do it on every hill, sometimes it had the extra power immediately but other times it was delayed.
     
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  3. Ok big boy

    Ok big boy Bobtail Member

    48
    46
    Jan 22, 2014
    0
  4. niceguypmp3

    niceguypmp3 Bobtail Member

    43
    8
    Aug 31, 2009
    Weldon, IA
    0
    I have looked on there but haven't posted about this issue. I will do that, thanks.
     
  5. Ok big boy

    Ok big boy Bobtail Member

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    46
    Jan 22, 2014
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    I owned a 2003 CX 613 with a E7 425 and a 10 speed. The engine was bullet proof , but pulling it would hesitate then I would feel some extra kick. I replaced the throttle position sensor. That helped quite a bit. I don't know if there is a way to test that. I do not know any thing about your automatic. I would be interested to see some replies. Good Luck!
     
  6. Brettj3876

    Brettj3876 Road Train Member

    11,257
    54,046
    Nov 18, 2014
    Land of local
    0
    Is it a 330/355 or a 355/380 maybe. Go to Rochester diesel and get a blixxton. Then if your still not happy they have injectors and a bigger turbo.


    Check for boost leaks 1st and take the charge air piping off and check the impeller shafts for damage and play

    Tuning & Modules | Diesel Injectors | Turbos | Nozzle Honing
     
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