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Control Module for Injection Pump (J399) - Audi A4, 2.5Tdi, Avant 2002, B6

seanr Jul 11, 2011

  1. seanr

    seanr A6 Exclusive

    Hi Guys,

    I don't get to the forum very often so apologies for not posting / adding to many threads.

    I have an Audi A4, 2.5TDi, Avant, 2002 that has been suffering from, lack of power, occassional misfiring low down in 2nd and 3rd gears, smoking when misfiring...

    The diagnosis is ...............Control Module for Injection Pump (J399) and the price for a new injection pump is £1,800 odd quid or £500 for a refurb...

    The car is now making a heavy misfiring sound on tick-over and a friend reckons that my problem is actually a faulty / failed injector but i could do with throwing this out for any help that anyone may have...

  2. quattrojames

    quattrojames Moderator Staff Member Moderator Audi A6 Audi Avant Owner Group

    It 'could' be either .....

    Injectors aren't cheap though...... depending on your friends ability I'd be tempted to go with the garages diagnosis.
  3. PAULF

    PAULF Active Member VCDS Map User

  4. JamesWoods

    JamesWoods New Member

    It could be your needle lift sensor which I think is part of No2 injector, its one of the injectors @ the o/s bank cyl 1 2 3, its the only one with a wire coming from it.
  5. adamss24

    adamss24 Well-Known Member

    I would do a scan first then take the rocker covers off and look for dislodged rocker arms. If the cams are badly worn then they can fail and get chewed by the engine wich may damage the heads... As sugested, needle lift sensor (built in the 3rd injector) can also effect the iddle and power delivery but also the control module of the pump.
  6. seanr

    seanr A6 Exclusive

    Hi Guys,

    thanks for the replies. just got the car back from a proper diag session and the probs worse than I thought:

    The cam under cylinder 4 is well worn and as such the valve is not opening properly (Pressure blowing the wrong way).
    The cam under cylinder 2 is also very well worn and has caused the rockers to jump out of position and snap two followers. (like you diagonosed Adam)
    There's also a hairline crack around one of the injectors..

    All in all the prices i';m getting for Cams / followers and hydrolic's is around the £1,200 mark without labour ...

    The car's going in for a 2nd opinion tomorrow but, I've got tears in my ears..

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