Wiring loom for an 18R-GEU

[Azair]

Hi I have just been given an 18R-GEU but I do not have the wiring loom or ECU.

Just wondering what I can use to get this thing in my 81' RA40? I saw a post about using 22R-E loom and ECU and have been advised I can get this for about $500 from a wrecker, is this good or too much?

What else could I use?

Thanks in advance and all help is extreamly appreciated.

[dumbass]

just buy a microtech for it
then u dont have to worry bout getting all the other missing stuff
instead of wasting 500 on something that will cost you another grand to get to work properly

[The Witzl]

plus i can attest that the factory 18RGEU efi system is shithouse - consider it an electronic carby.

Rather that a microtech, I would recommend an Adaptronic - they are cheaper, more flexible, and all round just better.
Both will come with a loom with bare wires, so you have to loom it up yourself and get plugs to suit - but getting plugs is EASY! A quick trip to your local self serve wreckers and you will find all the plugs you need scrounging in cars with engines like 5ME, 22RE, 2SE, etc.

The only plugs you need when going aftermarket ECU are:
- TPS
- Water temp sensor (the green one on the thermostat housing)
- Injectors x 4
- distributor (but you can adapt whatever you like here really)


When going with an aftermarket ECU, the BIIIIIG benefit is that you can now program ignition advance electronically, rather than relying on mechanical weights and vacuum diaphragms to control your ignition advance. To achieve this, you need an electronic dissy (18RGEU, or modify 18RC with 22RE dissy guts), and the advance plate needs to be "locked" or welded so that there is no mechanical ignition advance possible.
The signal from the dissy then goes into the ECU, and then the ECU fires back out a signal to an ignitor (you can use something like a Bosch ignitor) to create the spark.... and the ECU controls everything like dwell angle and ignition advance.

You will still be using the distributor to distrbute spark to each cylinder of course.


Trust me, this is a MUUUUUUCH better option that using factory ECU. Ive tried both, and its seriously night and day comparison.

[Taff]

You will still be using the distributor to distrbute spark to each cylinder of course.

I have never understood this. If the dissy is locked then how can it advance? I get it with coilpacks or coil on plug but, in this case, when the distributor is still sending spark out and the advance has been welded up wouldn't that make it static advance?

[The Witzl]

How do you think it works on modern engines?? None of them have mechanical advance in the distributor.
Is explain in more detail, but I'm using my phone and explaining requires a lengthy reply.

Maybe when I get to work.

[Azair]

"but getting plugs is EASY! A quick trip to your local self serve wreckers"

My problem there is I'm in the ACT and we don't have any self service wreckers that I'm aware of. My sister and her partner live near U pull it but I wouldn't trust them as the couldn't even locate a engine mount which was on the engine....

I really appreciate all this guys, the more info I can get the better. I would love to be able to do the job once and do it right!

I looked into the microtech option and they have come back with "if you are looking at a basic EFI setup then the stock dizzy will be usable and will work fine. You will be able to retain the single coil as well". Is there much work in changing from a single coil? What would the benefits be?

Again thanks heaps guys and please keep it coming :0)

[Taff]

How do you think it works on modern engines?? None of them have mechanical advance in the distributor.
Is explain in more detail, but I'm using my phone and explaining requires a lengthy reply.

Maybe when I get to work.

Modern engines dont even have a distributor. Your saying a locked dissy with the rotor still sending out spark to the cylinders can be electronically advanced. If the rotor cannot change position how is that possible?

[The Witzl]

Here are a list of example, just off the top of my head, where engines haev ELECTRONIC advance with a locked distributor.
4age
4afe
3sge
3sfe
5sfe
7mge
1ggte
1uzfe - yes... the lexus V8 has distributors.


... to name but a few from the toyota stables.



I cant be bothered trying to teach you, so please read this document to learn for yourself.

http://www.autoshop101.com/forms/h23.pdf

[dumbass]

basic expaination
dizzy has fixed timing input into ecu
say a pulse at 60 degrees btdc
ecu then calculates this and rpm
and ecu controls the output to ignitor or coil
so if ecu pulses coil or ignitor at 40 degrres btdc
then im guessing the timing will be 20 degrees

dizzy is just an input
ecu calculated what timing it needs
and adjusts the time it pulses coil to get timing right because it knows the input is fixed at 60
it then can adjuast the output

[The Witzl]

basic expaination
dizzy has fixed timing input into ecu
say a pulse at 60 degrees btdc
ecu then calculates this and rpm
and ecu controls the output to ignitor or coil
so if ecu pulses coil or ignitor at 40 degrres btdc
then im guessing the timing will be 20 degrees

dizzy is just an input
ecu calculated what timing it needs
and adjusts the time it pulses coil to get timing right because it knows the input is fixed at 60
it then can adjuast the output

its a little more advanced than that... but essentially that's how it works.

Read the document i linked to - that document was my bible for understanding how ignition systems work. its VERY informative.

[dumbass]

well u dont really need to know the rest
all the stuff is done by the ecu in the back ground
having wired up around 2000 motors i should know how it works

[The Witzl]

correct, you dont NEED to know... unless you are programing and tuning your own ECU and ignition system, which I have done when i did the Megasquirt-2 on my 18RGE.

[Invid]

Hey Azair, when I upgraded the computer and loom on my 2TGEU I was able to source some of the plugs from an auto electrician in Belconnen. Some I was able to source from Queanbeyan auto dismantlers and the internet. $500 is a good price and most of the plugs should match, but you get better performance and economy with an aftermarket ecu (it will cost more though). PM me if you have any questions or want to see whats involved.

[Azair]

Does anyone know if the plugs from an AE101 corolla loom would match those on the 18R-GEU?

[The Witzl]

no they will not fit at all.