MK2 8v k-jet problem

Discussion in 'K-Jetronic OEM injection' started by jimmy2gti, Sep 14, 2019.

  1. jimmy2gti New Member

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    Hello,
    I performed an injector test on the 8v GTI im restoring, and the results were rather disappointing.
    Initially I had a problem with the fuel pump, which I replaced and managed to bring fuel to k-jet.
    I put the injectors in bottles and gave power to the fuel pump. Upon starting the pump, the 3 and 4 injectors started spraying without lifting the metering head while the 1 and 2 barely dripped any fuel. Lifting the metering head had no effect at all and only after i switched off the pump the flow slowly faded away on 3 and 4 injectors.

    The car has been sitting for years and it had worked perfectly before that.
    I replaced the fuel lines prior to that test.

    Any k-jetronic experts able to tell me what could be the main suspects? Or the best thing i could do in my situation?
     
  2. dubztubz Forum Member

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    could be injectors
     
  3. jimmy2gti New Member

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    What could be wrong with the injectors
     
  4. dubztubz Forum Member

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    they just perish with age,just as example my own mk1 16v 4th injector packed in on me the other week.just out for spin and started running rough,no power lumpy idle.i stuck hazard relay in fuel pump slot at fuse box and did injectors test the 4th spray pattern wasn’t great so replaced it with s/h spare it’s solved it for now
     
  5. dubztubz Forum Member

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    https://ebay.us/F1ya2j

    New set off Mercedes ones are cheap tho depends on what year your car is as the injector thread changes
     
  6. rubjonny

    rubjonny Administrator Admin

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    use a 17/18/100 relay in the fuel pump socket ideally, as they've got the right side main power and output terminals to suit the socket. a 53 does work at a push though. first I've seen of indicator relay being used, I'll store that info for later :lol:

    as above if its spraying even on ignition then injectors or metering head is to blame, there should be no fuel injected unless the flap is lifted.

    have a read of the basic kjet troubleshooting tips in here:
    https://www.clubgti.com/forums/inde...air-and-tune-your-mk2-corrado-1-8-16v.195423/

    obviously ignore all the fancy 16v bits
     
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  7. rubjonny

    rubjonny Administrator Admin

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  8. jimmy2gti New Member

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    Thanks for your input. I eventually took a deep breath and decided to split the metering head. It appears that the plunger was completely stuck (it took a few hits with a hammer to get it out eventually). I cleaned it with special dissolvers and now with a tiny bit of lubrication it slowly slides on its own weight just like it should. The rest of the insides of the metering head looked surprisingly clean. I suspect that the problem on the 1 & 2 injection are the injectors themselves as theyre very old, im getting new ones anyway.

    Any other tips before I seal and reassemble the metering head? Any parts to clean thoroughly? What should I watch out for while reassembling it
     
  9. rubjonny

    rubjonny Administrator Admin

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    theres a handy pdf linked in that thread above, has all the info you need on meterign head rebuild :)
     
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  10. jimmy2gti New Member

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    Ok so, after taking apart, cleaning and unblocking metering head, and getting my hands on fresh injectors, I did the test again.
    The injectors 2 and 3 were finally working perfectly, only when i lifted the plunger. The rest were spraying on their own, even when the plunger was on rest position. I now took it apart agian. Should i just give up with this metering head or maybe there's a chance I could do something with it?
     
  11. rubjonny

    rubjonny Administrator Admin

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    sounds like its too far gone to be saved unfortunately, you can always have another try but no guarantee it'll be any better afterwards. the clearances inside these things are extremely tight so its probably just been damaged from old fuel or when freeing up the plunger
     
  12. jimmy2gti New Member

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    Just found a metering head with the same part no. in my area. Gonna give it a try..
     
  13. jimmy2gti New Member

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    Update:
    I got the metering head near me dirt cheap, didn't really have any expectations from it but here is how it performed "out-of-the-box" when i tested it in my golf:

    [​IMG]

    Needs some very fine adjustments, but I can say i got lucky!
     
  14. rubjonny

    rubjonny Administrator Admin

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    good stuff, should be sorted soon :)
     

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