Standalone wiring for 4agze

[neko-romancer]

Sorry to bother you guys again, but i posted previously about how my 4agze converted ae86 i recently bought was wired improperly. Well after puling the engine and taking of the dash to make everything easier, i noticed that when the previous owner had disconnected the ac controls, he had left the wires bare, and they grounded each other out and burnt/melted back into the main engine harness. As i said before the engine did turnover but was having starting issues and i figured they were due to terrible wiring. Even if i fix the wiring for the engine, i don't know how safe it would be or how long it would last even if i did get it running, with that burnt wiring. I've noticed after reading through these forums and others, that several of you and other have used standalone's like megasquirt or haltech to run your 4ag's. I am thinking that this would be preferable to trying to fix the wiring it has now, because it is all messed up. In this way, i wouldn't have to rely on the ae86 wiring, and wiring and correcting would be easier.?
I will already be doing everything to the engine that you guys reccomended previously ( jondee and yoshi )

So, my question is, how easy is converting something to standalone? It seems relatively complicated, but i am willing to try , if in the long run, it will make the car easier to work on/with. Do any of you toyota master craftsmen have any recommendations? Is there any 4ag engines that are easier to set up (like a standard na 4age or a 20v?)? I suppose i could sell what i have and attempt to try with a different engine... but i do already have this one.

the only wiring experience i have is wiring up an sr20 into an s13, and i suppose i can get some old men to help me with electrical stuff ( their experience will have been with tractors and stuff, so i don't know how well they will know fine car tuning/ electronics).
I don't really have any tuning experience either, but anything can be learned, if i try hard enough
I do have plenty of engine and car experience though ( i have rebuilt an sr20, and have done almost everything un-electrical or tuning based that you can do to a car.
i live in the texas panhandle, so i am pretty far from any experienced tuning shops, plus i like to do work myself

What i have:
levin converted 85 gts hatch
healthy ae101 4agze with a hks 254? cams and gts t50 tranny
W55 transmission with nitekids bellhousing and all the parts ( new 4agze clutch, bearings,forks, slave cylinder etc) ---came with the car---
All the parts needed to make the engine actually run
And am willing to buy more

Sorry for my newb problems

[neko-romancer]

Is using an mr2 harness do-able? I see that i can get mr2 harnesses pretty easily off ebay.

[jondee86]

Bit of an overview first

Factory ECU
Generally speaking, the factory does a pretty good job of putting the ECU
and engine package together. If no-one messes with the engine it will run
smoothly and reliably for a long time. It will start and idle nicely no matter
if it is hot or cold out; it won't stall at the lights, and it will pull cleanly from
idle to redline. If you just want to drive and enjoy your car (and not spend
nights in the garage trying to fix stuff) this is the setup you should choose.

Aftermarket ECU
If you modify your car to the point that it will no longer run decently on the
factory ECU, and you have a strong masochistic streak, you will need to look
at getting an aftermarket ECU. For old cars these are not plug and play. The
ECU is delivered with a long bunch of colored wires hanging out of the ECU
connector plug. You have to route these wires, trim them to length and fit
connectors to the ends to match your factory sensors. Parts of the factory
car harness will still be required for lights, dash inputs and accessories.

You will need to create fuel and ignition maps by hooking the ECU up to a
laptop and using the supplied software. If you are lucky, someone may be
able to give you a copy of their maps to get you started. But because all
modified engines are different, more fine tuning will be required.

If you choose to self-tune, after many hours of work, you may be able to get
your car running OK, but not as nicely as the factory ECU ran the stock engine.
If you bail on self-tuning, a dyno tune will get the engine running better once
you invest $1000 or so.

To Summarize
There is a lot of satisfaction to be had from installing and wiring up an after-
market ECU. You will learn how to handle frustration and disappointment, and
you will learn more about engines and engine management than you ever
believed possible You will need patience and be willing to study wiring
diagrams until you know the purpose of every wire in the engine bay. It will
build character and keep your mind off girls

If that seems like too much, consider repairing the existing harness. Here is
a link to an outstanding writeup on a GZE conversion....

4AGZE into AE86 Comprehensive Guide - DIY by shubert_ae102

Cheers... jondee86

[neko-romancer]

Damn!, i guess i will have to make decisions. I will have to figure it out i suppose. Serves me right for not buying a stock car and starting from there like i usually do

Yeah, i know of shuberts swap guide it is very good, the only problem is my car was swapped in the early 2000's, before that post ever existed , so they did everything the ass-backwards hard way. If you follow shuberts guide, not alot needs to be done and nothing really needs to be lengthened except a few things. Whoever did this one lengthened like everything and ran it this way and that.
I guess i will just have to try harder, Thanks jondee

[totta crolla]

Listed are a couple of links that may help you to work out what each pin does:
http://charmant4age.blogspot.co.uk/2010 ... g-pt1.html
http://charmant4age.blogspot.co.uk/2010 ... 2-efi.html

[neko-romancer]

^^^^^ , thanks, that looks like its going to be very useful