High idle issues when cold

Discussion in 'K-Jetronic OEM injection' started by mk2 nas, Jun 11, 2016.

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  1. MK2 NAS

    mk2 nas Paid Member Paid Member

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    As title,my idle is at 1700 rpm untill warm.(k jet1600 eg)
    I've read some threads I suspect it could be numerous things but ive got start with the Aav I think.
    Also idle screw don't seem to do much,anyone know the part number supplier for a new o ring for idle
    Screw.thanks:thumbup:
     
    mk2 nas, Jun 11, 2016
    #1
  2. rubjonny

    rubjonny Administrator Staff Member Admin

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    i just bought a big box of orings and used the closest size :) if that doesnt help you may have an air leak somewhere so strip all the pipework off it and look very closely at it for splits in hard to see areas
     
    rubjonny, Jun 13, 2016
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  3. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Thanks rj been too busy to look into this but had a good look today.cant see anything obvious to cause the
    High idle.but high idle does settle after a few minutes but won't go below 1100(idle screw all the way in)and it's got a good "o"
    Ring.
    If I squeeze the rubber pipe to aav when first started it reduces rpm to near normal.so my question is,is aav past it and not
    Serviceable.
    Also can an aav be bypassed with a modded pipe and a small ball valve so I can regulate the air as it needs slight air( I think)when closed right?
    New aav an option or obsolete now?
     
    mk2 nas, Jun 19, 2016
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  4. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Thanks rj been too busy to look into this but had a good look today.cant see anything obvious to cause the
    High idle.but high idle does settle after a few minutes but won't go below 1100(idle screw all the way in)and it's got a good "o"
    Ring.
    If I squeeze the rubber pipe to aav when first started it reduces rpm to near normal.so my question is,is aav past it and not
    Serviceable.
    Also can an aav be bypassed with a modded pipe and a small ball valve so I can regulate the air as it needs slight air( I think)when closes right????
    New aav an option or obsolete now?
     
    mk2 nas, Jun 19, 2016
    #4
  5. rubjonny

    rubjonny Administrator Staff Member Admin

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    apparently you can adjust the aav with an allen key or something, but you want to be 100% sure there isnt an air leak elsewhere or a setup issue before you mess with it!
     
    rubjonny, Jun 21, 2016
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  6. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Ok not sure it's 100% the aav.or the revs wouldn't drop after a few minutes would they?
    Cold start at 1600-1700 rpm dropping to about 1200 after couple mins.so maybe it's doing its job.the other thing my revs
    Don't seem to drop quick enough between gear changes either.stumped really as I think it's running quite well for power
    Etc just this idle thing that's f,kin annoying. image.jpg
    This is after a good drive.think the colour is ok.bit sooty on the base ring.your thoughts.
     
    mk2 nas, Jun 21, 2016
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  7. rubjonny

    rubjonny Administrator Staff Member Admin

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    That wouldn't worry me no, I'm still leaning (geddit?) towards a slight air leak somewhere, I think the next step would be strip the whole inlet system down so you can inspect everything very closely, replace the inlet and TB gaskets etc
     
    rubjonny, Jun 22, 2016
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  8. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Ok going to have to be a bit more in depth I think with the excess air intake.seems strange though idle settles when
    Hot running ,but if I switch of engine and restart say 20 mins later the high idle returns.but the aav would be closed with residue heat.stumpted.
    Start squirting some stuff around intake and see if revs change.
     
    mk2 nas, Jun 23, 2016
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  9. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Ok going to have to be a bit more in depth I think with the excess air intake.seems strange though idle settles when
    Hot running ,but if I switch of engine and restart say 20 mins later the high idle returns.but the aav would be closed with residue heat.stumpted.
     
    mk2 nas, Jun 23, 2016
    #9
  10. MK2 NAS

    mk2 nas Paid Member Paid Member

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    I've discovered that aav has no power to it.so am I right in thinking its waiting on engine heat to close over rather than
    the electrical plug.therfore taking longer than it should.how long would it take to close with/without power.
    Anyone.
    P.s would the difference be that dramatic.
     
    mk2 nas, Jun 25, 2016
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  11. rubjonny

    rubjonny Administrator Staff Member Admin

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    it would take a lot longer to close as it would rely on radiant heat and there wont be much of that since its not directly attached to the block.

    the WUR and AAV are both powered from the fuel pump relay, on the older ceramic fusebox the wires from them run to a clear plastic spade jumper block near the A pillar. tyhe fuel relay output and fuel pump power wires all run to this point so I would start there. make suree the brown wires have continuity to ground also, these should be earthed to the claw above the fusebox
     
    rubjonny, Jun 27, 2016
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  12. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Oh dear what a mess,the fuel pump has been hard wired to ignition live so I now suspect the wur is also on engine heat only.
    I understand the importance of a fuel pump relay shutting off fuel flow in the event of a front smash.wouldnt fancy being
    Doused in fuel while trying to escape:(.
    I'm gonna have to somehow put it back to stock,I'm thinking just a few wires to the right places but not likely the origonal
    Ones as they obviously had an issue with it.may need some good advice with this one.on the bright side they did leave the
    Relay in the glovebox saving me a few quid.every cloud...:o
     
    mk2 nas, Jun 27, 2016
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  13. rubjonny

    rubjonny Administrator Staff Member Admin

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    a common fault with the ceramic fusebox is the /5 pump power pin burning out as its not adequate for the load, or if someone put a non-gti fusebox in some of them dont even have the fuel pump power pin.

    vw had a factory recall on them which involved moving the relay above the fusebox, they had a plug that pushed into the front to take the ignition and rev counter feeds out and it was wired straight to the live spades up top plus the fuel pump power distribution spade block i mentioned earlier
    [​IMG]

    you can do similar but tap into the coil power wires direct for ignition and rev counter, put earth to the claw:
    30 - permanent live - spade H
    31 - earth - to claw
    31b - trigger feed - red/black wire on coil -ve
    15 - ignition live - black wire on coil or spade G/3
    87 - to fuel pump power distribution jumper block

    http://www.clubgti.com/showthread.php?219775-Fusebox-FAQ&p=1945620&viewfull=1#post1945620
     
    rubjonny, Jun 27, 2016
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    mk2 nas likes this.
  14. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Not what I was expecting, but fixable.im not the best with auto electrics but I will have a good look at what you've posted
    And more than likely give it a go. it can't stay hard wired it's just wrong.although I'm sure there's others out there.:o
    I suppose buying a 34year car was always gonna throw up problems.
    P.s it has the 15 fuse bullet type board.
     
    mk2 nas, Jun 27, 2016
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  15. rubjonny

    rubjonny Administrator Staff Member Admin

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    just make sure you use a propwer s1 relay with fuse built in, or if you fit a later plain relay from s2/ce1 then put a 15a fuse inline with the live input pin
     
    rubjonny, Jun 27, 2016
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  16. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Ok,just found this in a bag of bits that was in the boot from ages ago. image.jpg
     
    mk2 nas, Jun 27, 2016
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  17. rubjonny

    rubjonny Administrator Staff Member Admin

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    good start! that one you need a proepr s1 relay, the s2 have bigger terminals and wont fit the holder
     
    rubjonny, Jun 27, 2016
    #17
  18. BLIS

    blis Forum Member

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    I cant help but chuckle. Some owners just worry about getting from point A to point B and tell you a car is working perfectly, then a Vw lover buys it... good work guys on sticking with it!
     
    blis, Jun 27, 2016
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  19. MK2 NAS

    mk2 nas Paid Member Paid Member

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    Think I can sort this,couple of q,s where's spade h ?

    Trigger feed 31b just connects to red/black on coil right?what's Ve??? & g/3
    Apologies for all the dumb questions wanna get this right first time.:thumbup:
     
    mk2 nas, Jun 27, 2016
    #19
  20. rubjonny

    rubjonny Administrator Staff Member Admin

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    click the fusebox faq link in my post, shows the back of the fusebox for ya :) H is the group of spades near the fat reds, all permanent live. G spades are across from them and are various accessory feeds, spade number 3 is ignition live :thumbup:

    31b to the coil red/black yes, dont cut the wire though as it also feeds your rev counter. so splice into it. -ve means negative :)
     
    rubjonny, Jun 28, 2016
    #20
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