How to test measure injection quantity and hammer mod

Discussion in 'General Diesel Discussion' started by chittychittybangbang, Jun 13, 2009.

  1. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    22,059
    Car:
    2006 Jetta TDI
    Location:
    CT
    http://www.myturbodiesel.com/1000q_how_to/multi/IQadjusthammermod.htm

    If you've never checked the fuel injection quantity on your 1996-2003 TDI it's possible it's off. Included are VCDS menu screenshots and how to do the hammer mod.

    Fuel injection quantity (IQ) adjusts power, smoke, and economy. It can be misadjusted from the factory or it can change after a mod to your car. The middle section of the injection pump adjusts IQ using an electronic arm. However, the electronic arm has mechanical limits. The hammer mod changes the mechanical range of motion on the arm.
    login to remove this ad
  2. BillK

    BillK New Member

    Joined:
    Aug 29, 2007
    Messages:
    78
    Very detailed! What is the typical range that you can adjust the IQ through the software?
  3. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    22,059
    Car:
    2006 Jetta TDI
    Location:
    CT
    It depends on where the mechanical limits of the quantity adjuster are. If it's already at one end the software can't adjust it further in that direction.
  4. fstjetta

    fstjetta Member

    Joined:
    Aug 24, 2007
    Messages:
    147
    This is pretty much a free power or economy mod. You CAN feel the difference after adjusting IQ.
  5. Bobbyk

    Bobbyk New Member

    Joined:
    Sep 11, 2007
    Messages:
    47
    Very informative, thanks for the explanation.
  6. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    22,059
    Car:
    2006 Jetta TDI
    Location:
    CT
    More notes added. And just to clarify, you can check IQ on pump duse engines but you cannot change IQ on them (at least for US engines, euro may be different due to different engine management system).
  7. Superbass

    Superbass New Member

    Joined:
    Nov 9, 2007
    Messages:
    142
    That's why you get a chip :) big :) !
  8. MrSafety

    MrSafety New Member

    Joined:
    Feb 10, 2011
    Messages:
    6
    Car:
    '81 VW RABBIT "Caddy" P/U - 1.6L D - 5-spd Man.
    Mods:
    Restored F&R suspension/exhaust sys/new 5-spd Tran
    ... As a "Newbie" this is my first POST on MyTurboDiesel.Com FORUM...

    ... As a "Newbie" this is my first POST on MyTurboDiesel.Com FORUM...
    and the title of this [edit] THREAD [<-edit->]makes me inclined to think this is about:
    either adjusting the IQ using VCDS OR doing it by the "Hammer Mod" method...
    but then when I read and study this more closely,
    I wonder after reading the photo captions near the end...
    I wonder if the title could also read:
    "Set your IQ with the Hammer Mod [<-edit->] first for the lower limit of the range AND then use VCDS to set upper range!" [<-edit]
    Q1 - Am I missing something as a Newbie...
    or is my suggested title more clear as to this POST's intended message
    ?


    Here is why I ask:
    After a 3-week "No-Start" project, we recently faced the decision to send in or replace our 2002 Jetta TDI's IP and we ended up taking the top of the IP and found the QA shaft frozen.
    While connected by telephone with DFISpdx.com in Portland we then removed the next section ["QA assembly" (my name?)], freed up the shaft, cleaned things up and put it back together. Yes we marked the IP's adjacent case sections and replaced things very precisely... but it had a very bad/rough idle and so we ended up at a local INDY VW shop with a Ross-Tech system & "some" experience and he was able to cure the idle problem.
    So:
    Q2 - Should we redo the QA after first performing the IQ by first the "Hammer Mod" method and then use VCDS to set the upper limit?
    Thanks in advance...
    I really like your collection under your pages"
    "1000q" and "1001q/multi" !!
    Regards,
    Sam Ross / Novato, CA
    Last edited by a moderator: Feb 12, 2011
  9. Fluid

    Fluid New Member

    Joined:
    Jan 17, 2008
    Messages:
    482
    I would use the default software value and then do the hammer mod so that it's in the middle. This way you have more room to move with the software. If it's running well now, I wouldn't touch it.
  10. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    22,059
    Car:
    2006 Jetta TDI
    Location:
    CT
    1: it should ideally be set to optimal but sometimes it just isn't. Set to middle of range.
    2: To the best of my knowledge, VCDS adaptation can not set the upper or limit. It merely sets the adaptation. The ECU map and physical limit of the QA controls the upper and lower limits
  11. MrSafety

    MrSafety New Member

    Joined:
    Feb 10, 2011
    Messages:
    6
    Car:
    '81 VW RABBIT "Caddy" P/U - 1.6L D - 5-spd Man.
    Mods:
    Restored F&R suspension/exhaust sys/new 5-spd Tran
    ... Clarifications PLEASE...

    First let me clearly state that in this my 2nd POST on this FORUM is to LEARN...
    and right now specifically to LEARN about the VE-e series of IPs and their actions/reactions with the car's "ECU"/"ECM"...
    so let me ask for clarifications in both of your kind & prompt responses:
    [note that it helps my aging brain to break down such written dialogue with each sentence and/or phrase starting on separate lines... probably dementia setting in upon my 67 year-old gray cells]

    OK, I'm a 67 year-old who many decades ago was a U.S. Naval communications officer and combat air controller [Vietnam] and this experience ingrained in me the fact that oral communications (dialogue) can far more readily cause misunderstandings than written communications...
    but here too in such "written" FORUMs this engineer has learned that there are pitfalls... mostly born out of brevity!
    So don't take me for "nit-picking" anyone here...
    just trying to learn how these TDI systems work...
    and then to work on my Son's car so that it works better!
    Best regards,
    Sam

    P.S. - Please let me know IF you think I use too much color... or need a little more "brevity"!
    P.S.S. - Yes, I came to this FORUM by way of the www.TDIclub.com FORUM.
    Last edited by a moderator: Feb 12, 2011
  12. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    22,059
    Car:
    2006 Jetta TDI
    Location:
    CT
    I don't think adjusting IP will shorten life expectancy of anything. More advanced timing, within a range, can raise stress and temps but I don't think it makes a difference in engine lifespan or will kill the injection pump.

    To the best of my knowledge, the ECU map sets the upper and lower software limits. The physical range of the QA arm sets the physical limit. When properly assembled from the factory, the physical limits should not be limiting the software. However, this is often not the case.

    You can do some adaptation to change this within the overall software mapping but the ecu map is the "superior" determining factor, the adaptation is the "inferior" factor. This is just how I understand it, I could be wrong. Feel free to start another thread in the Ross tech section under the general forum here asking about how adaptation of the IP works, they would know more and they respond quickly.
  13. MrSafety

    MrSafety New Member

    Joined:
    Feb 10, 2011
    Messages:
    6
    Car:
    '81 VW RABBIT "Caddy" P/U - 1.6L D - 5-spd Man.
    Mods:
    Restored F&R suspension/exhaust sys/new 5-spd Tran
    ... Where is this FORUM's glossary?

    By all means... where is this FORUM's glossary?
    I need to study TDI terms much more than I have!
    Thanks: "chittychittybangbang" & "Fluid"
    for the IP lessons!
    Sam

Share This Page