ej20TT loom question

Radeon · Post by **Radeon** » Sun Jul 09, 2006 3:24 pm

Ok, I have a damaged 94 legacy with an ej20 twin turbo engine. The engine is in very good condition so i want to put it into a new legacy body. The body I have bought is exactly the same, it has the same ej20 twin turbo engine, and is of the same year as my damaged one. I would like to know if i can just swap the engines over without having to change the loom as well. The computers are different, one has MU written on it, the other KE, also one is a BD5 model and the other is a BG. Is this going to be an easy swap or a real bitch of a job?
I am also converting it to manual if thats of any concern?
Help is much appreciated.

Chris_Rogers · Post by **Chris_Rogers** » Sun Jul 09, 2006 4:29 pm

would be quicker to swap teh lot I figure. seems (from reading) that the computer addresses teh 2nd turbo in a different fashion in the later ones.

(I have a BG5)

when you are pulling the BG5 apart can you grab the numbers of the ABS module under the drivers seat please.

jzk25 · Post by **jzk25** » Sun Jul 09, 2006 4:45 pm

I think you are looking at the auto trans computers not the engine control. You need to know the actual age of both cars more importantly. BD5 is a sedan, BG5 is a wagon, it doesn't have much to do with the engine type. The age of the cars does however, the wiring systems and ecu changes in 10/96. Either way you can still swap over the long engine with the manifolding from the original car.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 7:13 pm

Yea both cars were built in 1994, so does that mean i will b fine not having to swap looms?
And if im looking at the auto computers where is the engine one?

Chris_Rogers · Post by **Chris_Rogers** » Sun Jul 09, 2006 7:16 pm

engine should be in the p[assneger foot well. trans one starts with 317 and is on one side of the steering column.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 7:17 pm

Yea thats where the auto one is then, cool thanks il check the engine one. If its the same will i have any problems keeping the looms where they are?

Radeon · Post by **Radeon** » Sun Jul 09, 2006 7:20 pm

The cars were both built in 1994

Chris_Rogers · Post by **Chris_Rogers** » Sun Jul 09, 2006 7:25 pm

if you are doing a full strip - none at all. every thing will come out and go back. what are you doing with the spare harness? ( I need the rear part of it with the ABS harnesses/ plugs)

Radeon · Post by **Radeon** » Sun Jul 09, 2006 7:28 pm

Im very pressed for time so REALLY dont want to swap the loom as well. Do u know if it will work not swapping them?
Umm, not sure about the other loom, unsure if the engine is repairable. Depends how much you are willing to pay for it.

Outback bloke · Post by **Outback bloke** » Sun Jul 09, 2006 8:02 pm

Probably not what you are wanting to hear but ...........

Using a manual with auto loom will work but not properly in my opinion. If it was my car I would swap it purely for the gearbox aspect of the loom. The ecu will run both motors though.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 8:03 pm

But the manual box wont have one right? so is it going to matter at all? Is it going to do bad to something?
I have done the exact thing with an ea82T and it was fine so thats what im basing this on

Outback bloke · Post by **Outback bloke** » Sun Jul 09, 2006 8:11 pm

That is the problem really. The TCU (transmission) talks to the ECU (engine) and vice versa. With the manual not having one you will create issues between the two. It will work and run but not as well as with the correct harness. I believe it will retard the timing (loss of performance) to "protect" the engine as both control units will be giving fault codes.

I would say put the motor in out of the damaged one and your gearbox and KEEP the old loom intact and be prepared to swap it.

jzk25 is a full on wiring nerd on these things. He would know a way around the issues but they would be quite involved. Swapping the loom is really not a big job and could easily be done in a weekend by you and a mate.

Outback bloke · Post by **Outback bloke** » Sun Jul 09, 2006 8:13 pm

BTW, if you are going to part out the spare twin I wouln't mind buying a few things from you.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 8:18 pm

Well the car im swapping it into is also auto! lol so i guess im screwed. Umm yes i probably will dismantle it, i also have an ej20 single turb from an 89 RS which i am dismantling, what are you after?
Oh, and cud i take the car somewhere to get those ecu problems sorted out?

Outback bloke · Post by **Outback bloke** » Sun Jul 09, 2006 8:51 pm

Just thinking out loud about it. If you can get your hands on a manual ecu from a wrecker over there you might be fine. Just not 100% sure. I have done auto to manual single turbo conversions and they just aren't happy. They work and all that but always seem to be down on power to a "straight" manual factory one. Thinking about it, we have never actually just fitted a manual ecu when the box went in.

Umm yes i probably will dismantle it, i also have an ej20 single turb from an 89 RS which i am dismantling, what are you after?

Thinking about rear diff, fuel pump, steering wheel, seats, side skirts etc. PM prices if you want, once you sort out what you are doing with it. There is a stack of gear coming from Japan but it always pays to keep your options open.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 8:55 pm

Oh yea im prepared to sell that sort of stuff right away cos i wont need that. make me an offer on each of the bits, iv never dismantled a legacy before. Thanks for the help on the loom, i will just keep the looms where they are and investigate further when i have the car on the road.

Radeon · Post by **Radeon** » Sun Jul 09, 2006 8:58 pm

What if i just remove the ecu for the auto box?

Chris_Rogers · Post by **Chris_Rogers** » Sun Jul 09, 2006 9:49 pm

lateral thinking would dictate taht teh manual would have the TCU settings turned off. I remember reading on UK site that the car was down on power with the auto ECU/manual box as well.

(think it was a yahoo group - stick the ECU part# in google and it should come up- thats how I found it.)

mattims · Post by **mattims** » Mon Jul 10, 2006 7:27 am

i think either ECU will run manual or auto. There will be a line going into the ecu that tells it wether the car is manual or auto (dont know what wire sorry). As these ecus have the fuel spark boost etc tables for manuals and autos in them.

jzk25 · Post by **jzk25** » Mon Jul 10, 2006 8:41 pm

BYB-01 wrote: jzk25 is a full on wiring nerd on these things. He would know a way around the issues but they would be quite involved. Swapping the loom is really not a big job and could easily be done in a weekend by you and a mate.

I've never been called a nerd before.

Auto and manual ecu's are the same in the early TT's but the auto has torque cut and torque permission communication with the TCU. It also creates a MAF signal for the TCU.
It doesn't matter if you remove the auto and fit a manual, the engine will run the same. The problem with manual TT's is there on factory manuals too not just converted cars.

There is some minor rewiring to do to when you change to a manual, specifically with the neutral switch which is wired into the starter circuit. I will have to check the diagrams to get into specifics.

To avoid any problems with manual TT's you really need to either have an auto TT or a manual single turbo. I have never driven a manual TT that delivered the goods.