Mk3 Gt conversion, got some questions?

[dubdom]

Hello people,

I'm part way through putting a GT engine into my mk1, and have got a couple of problems. Lots actually...

1. Reverse light sensor?
Only have the actual engine loom in the mk1 not whole front loom. Could i just swap the switch out of the mk1 4 speed into the mk3 5 speed? (That would save me lots of hassle)

2. Fuel pump wiring? Locating the fuel pump at the back beside wheel well (mk3 polo stuff). Have the in car fuel pump wiring but were does it go? Do i take some wires from the back of the relay beside the ecu. (unless you can guess I'm a complete wiring novice)

3. Black temp switch on thermo housing? haven't got the right plug as far as i can see. Where does it go and what should i use?

4. Unknown plug no.1, furthest forwards one on the little mount of 3 beside inlet manifold. Again catn find correct plug, 2 pin plug with yellow and blue wires going to seperat plugs on back of the head? What is?

5. Unknown plug no.2, This plug run along with the plug to the coil pack but splits before it reaches, its a 3 pin plug (brown red black wires) What is?

6. Unknown plug no.3, This one runs along with main loom towards the ecu but again splits, its a 3 pin plug with a big red, little red and a yellow? What is? anything to do with fuel pump??

7. Coolant inlet, outlets?? Thermostat housing, 3 outlets on back, top two are plugged lowest is not, where does it go? Other two are on the metal coolant pipe running along back of block, two outlets coming out towards back on the far right (looking from front). I assume two of these go into my heater matrix, but which ones and what does the other one do???

8. Coil wires, all of the wires to the coil and other mk1 wires, hall sender etc which will not be in use, i assume theres an ignition live which ill be using but what do i do with all the rest?

9. Coil pack, where have other people chosen to mount it, dont really want to cut loom so that restrict things, also what dizzy-coil pack lead could i use which is longer?

10. And finally has someone got a pic of the fabricated gearbox mount? Just want to see one before i start to cut them about? (for adapting 4-5speed, mk1 to mk3??)

Phew......... Right those are all the questions I've got, just wanted to see if anyone can offer any advice?

As you can tell i am by no means a pro, so dont hesitate to put anything in lamens terms........

I really appreciate any help anyone can offer

Cheers,

Dom

[rubjonny]

1. could try it, should fit if your MK1 is a 1.0-1.3
2. you'll need to either fit a MK1 fuel pump relay & wiring, or splice the Polo wiring in somewhere. The problem with the polo is it uses a completly different type of fusebox and its sat in the rain tray
3. you'll need to find a suitable plug for this, they're dead common on later VAG models though. chop off and fit it to your red/yel wire, run the other wire to earth somewhere
4-7, pics would help. these all sound liek managment wires that will be part of the polo ecu loom. what you need to do is strip the polo ecu loom down to the bare components, remove anything thats not for the ecu. then strip all the engine bits out of your mk1 loom, and cobine the 2.
8-9. The polo coil has 3 pins, earth (brown), ignition live (black) and the trigger wire from the ecu (usually red/green), no biggy to wire up.

however you'll need to watch out here, otherwise your rev counter wont work.  2 ways for this, either bin the polo coil and fit a later MK2 Golf/Polo electronic ignition loom & coil, and splice to the MK3 polo coil wiring or open the polo coil and add a wire into it for the rev counter.
If you used a MK2 coil you would need the TCI-H unit and wiring between it and the coil. Then splice the wire from pin 6 of the coil into the mk3 polo coil trigger wire.  run your mk1 rev counter wire to terminal 1 on the mk2 coil and job done.  Advantage here is the coil will fit in the factory spot and use the std ign live and rev counter wires from the MK1 loom.

[dubdom]

awesome cheers dude thats a great help, im gonna get a chance to get onto it today or tomorow, ill grab some pictures and see what i can do and update this.

[dubdom]

right did a fair bit this morning, oil high and low pressure switches, one odd thing was that what i had labelled as yellow pressure switch was a blue wire, and what i labelled as blue pressure switch was yellow. This was a fair amount of time ago when i took it out so i dont really know what i did, oops.

i have still got a couple of problems so i thought id take some pictures and see if anyone can help.

There are two plugs which i dont know what they are, they are the same type of plug. One which goes close to the coilpack and split just before it.



Second one is close to the ecu. (far right)



close up of the plug



Also this red wire and brown wire i assume is power and earth for ecu?



Next was those coolant inlet outlets. you can see all 3, 1 plastic and 2 metal ones, i have got two pipes coming out of mk1 for heater matrix, dont know which ones they go to and what the other thing is?



Other two things were a couple of breathers, first coming out from under inlet mani (as far as i can see) has a red tip on it, cant see any logical place for it to go to.



second is one coming from back of dizzy.



where do these go and what do they do?




The only other thing i have to sort is fuel supply. Lift pumps in, but i need the plug, its a 3 pin plug, i assume one is earth, one for level sensor and one a power for pump? were will i run the power to? cause i assume its gotta have the relay which is up by ecu.

Also just gotta run power to pump and mount the pump aswell.

Cheers for any help once again!

[rubjonny]

1-3 I think you would be better off asking on clubpolo, its been too long since ive worked on a polo!  i recognise plug #1 & #2, but I cant for the life of me remember where they go.  1 might be for a knock sensor? 2 looks like it could be power, fuel pump and a starter motor? there is a similar plug on a digifant mk2, and red/yel is usually fuel pump power or relay trigger. the fuel pump relay is there in the loom so id say it could be power to the pump(s)

can you list the wire colours on these 2 plugs?

4 - yeah to the battery, which is in that corner of the scuttle on a polo. Need to extend em!

5 - left one on the metal pipe goes to the matrix, as does the spare hose onm the plastic flange. right connection on the metal pipe goes to the header tank

6-7 again club polo best place to ask, not worked on a GT before.  this pic any help:


Yeah you have earth, pump live and sensor output on the lift pump, opower will come from the fuel pump relay. im reasonably sure it goes to plug #2 for power.  Once you get the ecu powered up,  check for power at the red/yellow wire when you hear the fuel pump relay click on then off

[dubdom]

Sweet cheers, yeah I've got a post up on clubpolo aswell. So would power for Lift pump and normal pump come from the relay?

Just had a look at wires, no1 is red/yellow red/black and yellow. And the female plug on polo loom goes through the White plug next to the polo fuse box.


No2 is black red/black and brown and the female plug is closer to the front of the loom.

Cheers dude!

[rubjonny]

i recon the 1st plug is:
red/yel - power to fuel pump
red/black - starter motor live
yellow - diagnostics

other plug might be starter or fan related perhaps, cant recal. polo forum should be able to help though! i can remember unplugging that when i removed the head from the engine, but not where it actually went!

only a reasonable guess on my part though ideally you want to get the multimeter out and check for continuity to the ecu/relay pins. if it helps i have a polo gt wiring diagram?

[dubdom]

that would be great please mate. cheers for help!

[dubdom]

just got a reply on clubpolo sayin that one of the metal coolant outlets was for the expansion tank, and i asssume the breather in the last pic is for that aswell?

I am trying to do away with the expansion tank as its just messy, ive got my mk1 top fill rad in at the mo, would it cause any problems if i justy blanked them off?

Dom

[rubjonny]

yeah 1 of those is for the header, other 2 are for the heater matrix. no problem blocking one of the pipes off, just make sure it wont leak!

pm me your email address and I'll send the diagrams over.