OEM management wiring: 1.8T => Mk2 harness install FAQ

Discussion in '1.8 & 1.8T' started by 20v_jimmy, Dec 29, 2009.

  1. 20v_jimmy Forum Member

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    Yea it will definitely be interesting to compare how you have done things. Mine is all sorted now, been driving it around daily for the last week or so. Just got to check it with vagcom again to see how its doing as far as fuel trims with the 225 injectors, although i now have a set of the correct ones to go in.

    Oil pressure wiring i left exactly as it is in the mk2 and simply used a T-piece to fit the two sensors to the single port. Oil temp i fitted into the port on the 20v which originally had a blanking plug in it and again used the standard mk2 wiring. Water temp, i used the mk2 wiring and mk2 sensor in a housing from a mk4 golf with air con as this has an extra port for a sensor.
     
  2. Dan_Mk3GTi Forum Member

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    Excellent guide :) How relevant is this to mk3 wiring?
     
  3. 20v_jimmy Forum Member

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    Should be pretty much exactly the same for a mk3, they both use a ce2 fusebox. Only things which may vary are what the original wires from the g1 connector went. Id check this and make sure that you can still use the same pins, rubjonny's FAQ in the electrical section should let you do this pretty quickly.
     
  4. Dan_Mk3GTi Forum Member

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    cheers I'll go check it out :)
     
  5. nrich vw New Member

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    Hi fellas, i've done this conversion into my 1989 mk2 but i have a ce1 fuse box do you know any links for any one who has conected this engine to this fuse box as im scratching my head a bit. cheers
     
  6. benthejettaman Forum Member

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    just look at rub jonny fuse box guide, you should be out to work it out from cross refrencing the 2 fuse boxes
     
  7. nrich vw New Member

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    I kind of have but there is still a lot of guess work matching things up, the ce2 fuse box has more connections free than the ce1 as well. Guess i'm going to have to just connect what i think matches and see what happens then. thanks
     
  8. Dan_Mk3GTi Forum Member

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    edit: removed as it was a stupid thing to say!
     
    Last edited: Nov 17, 2010
  9. rubjonny

    rubjonny Administrator Staff Member Admin

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    CE1 has everything you need except you dont have the ecu relay wires if you dont have a digifant engine loom to cut up. no big deal, in this case i mount the ecu relay above the fusebox. the fuel pump relay needs a trigger feed to D/13 and the rest should be pretty obvious. I'm doing a CE1 1.8T loom right now, my main headache is knowin exactly what bits can be removed with relays, and what relays definitly work. there are lots of conflicting reports around over which ones to use and which ones do work
     
  10. Dan_Mk3GTi Forum Member

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    I'm gonna be running this in a mk3 running a sports cat, could someone please tell me the parts removed in this guide that i'll need to keep if running a cat?
    Cheers
     
  11. 20v_jimmy Forum Member

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    You can still remove all the stuff listed in this thread if you wish. However if you are keeping a cat then you could also keep the rear lambda sensor, and the secondary air injection if you wish. The rear lamda sensor basically just tells the ecu if the cat is still functioning correctly. The secondary air injection adds extra air to lean the mixture and create hot exhaust gasses to heat up the cat when the engine is started.
     
  12. Dan_Mk3GTi Forum Member

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    Will I encounter any issues come mot time by removing the sai and lambda stuff? I'm not too worried about codes as long as its running properly :)
     
  13. Dan_Mk3GTi Forum Member

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    Been hunting around and found the answer to the above question is no :)

    However I do have a new question, I was going to try and do my loom over the next few days bit having another quick read of the thread I realised I dont have any mk4 relays or anything! Do I need to use the mk4 relays and relay/fuse holder or could I make something up?

    Cheers

    Dan
     
  14. rubjonny

    rubjonny Administrator Staff Member Admin

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    no you can splice the loom to use the mk3 ecu and fuel pump relays. the box in the engine bay has the ecu relay and the secondary air pump relay, air pump relay and wiring just bin as not needed, ecu relay work out which wires goes from relay to ecu and splice this to your fusebox pin G1/10
     
  15. Dan_Mk3GTi Forum Member

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    thanks for fast reply!

    sounds easy enough, cheers man very helpfull as always :)
     
  16. nrich vw New Member

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    Hi fellas, I was just wondering what exhaust systems people had used on the mk2 1.8t conversion. I have used a standard jan speed decat down pipe, modified it and the bulk head to fit under the cable shift mk4 gear shift box. What I really want to know is, is it better to use straight through system or keep the three boxes?
     
  17. gtibadger New Member

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    Alright fellas,after looking through both rubjonny's and 20v_jimmys threads etc, I have to ask. As I'm doing this to my mk3 with an agu set up. My question is, am I right in thinking the loom is pretty much the same,bar the sai and dbw plug and a couple of others? Also in answer to dan gti, I found out my self that the pins in g1 on a. Mk3 ce2 fusebox, are similiar, once I get pin out datas from autodata, I will post up the pins needed from the. Mk3 and where they are and what colour. I will also do a full write up with a finalised wiring diagram for the mk3. Providing the agu loom is near enough the same as what were looking at here! Thanks in advance lads!
    Badger
     
  18. gtibadger New Member

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    as promised here is the wiring instructions for mk3, using some of RJ's and some of 20v_jimmys and my own . if you notice any mistakes please edit!

    T6-brown connector
    pin 1 -black or black/purple 15 amp fused ecu live switched --->black,black/white pin 38--g1 pin 4



    pin 2 - purple/white ecu to fuel pump relay earth ---->yellow/blue pin 31 -- g1 pin 3


    pin 4 - red/green 20 amp fused constant positive 30 to ecu ---->take live from fusebox 20amp


    pin 5 - blue/yellow fused 10 amp from fuel pump relay --->g1/10 red blue




    T14a - 14 pin connector near battery

    pin 5 - red/purple 10 amp fused switched live to injectors ---->Z1 - red/blue - fuel injectors



    pin 6 - yellow/black fused 10 amp from fuel pump relay ---g1/8 red/ yellow


    pin 7 - brown ecu earth --->pin 1 brown mk3 ecu-g1/pin 7? permanent earth


    pin 9 - brown/white earth for senders g1/6 .earth for senders. trace from pins to check!


    Diag port;
    Pin 4; earth
    Pin 7; k line to ecu pin 43
    pin 16; fused switched live
    Pin 10; battery live


    T10W -White connector
    pin 4 - white/red to clutch pedal switch (Clutch pedal switch in car)-using vw brake switch
    other side of terminal to earth


    T10 Orange
    pin 1 - grey/white to ecu T121/43 (229) -pin 7 of diag port
    pin 2 - green/red to ecu T121/81 (Tach signal from ecu to G1 pin 12)
    pin 6 - blue/white ecu T121/54 to speed signal in dash wiring (Hall speed sensor on clocks W pin 1)
     
  19. A.N. Other Banned after significant club disruption Dec 5th 2

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    Approved post ^^
     
  20. gtibadger New Member

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    Wooow. My first one! I will upload my own build thread soon and introduce myself properly!
     

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