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

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.

 

Excellent guide How relevant is this to mk3 wiring?

 

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.

 

cheers I'll go check it out

 

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

 

just look at rub jonny fuse box guide, you should be out to work it out from cross refrencing the 2 fuse boxes

 

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

 

edit: removed as it was a stupid thing to say!

 

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

 

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.

 

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

 

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

 

thanks for fast reply!

sounds easy enough, cheers man very helpfull as always

 

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?

 

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

 

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)

 

Approved post ^^

 

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