GT4 - Gen2 to Gen3 Conversion

[UMP-man]

Hi guys, I have recently discovered that to get the ST205 gear to work in my ST185, I will need to make modifications to the loom. I am planning to use the Gen3 Loom.

For those who have done this conversion, how much work is involved? Is it going to cost me an arm and a leg? Can I do it myself? Or is it too much of a puzzle? JustenGT8 said " not a job for the faint hearted"

Also can anyone recommend someone for the job?

Thanks.

[-==L=a=N=c=E==-]

to my understanding.... this is what you need to do.

remove the ST185 loom, and seperate the loom completely. So you have the engine controls side of the loom(ecu and engine control), and the chassis side of the loom.(fuse box and light wiring etc...)

You will find doing this that you will have a main power wire and main ignition wire coming from the fuse box and battery connector. This you'll need for the ST205 side of the loom.

The same needs to be done to the ST205 side of the loom, split it so you have the engine control loom and chassis control loom as one piece.

and then comparing the wiring layouts from both cars, mix and match and join the appropriate wires in the right places for power, and bobs your uncles aunty.


thats the theory, actually doing it may be a bit more interesting.

[milosamun]

I don't know about celica's, but I have done conversions on mr2s. I'm pretty handy at the old spannering having done backyard work for many years on many models, but the wiring loom is a big sticking point for any home mechanic. The problem I found is that it is not a simple rewiring exercise as there is enough differences to be annoying. I also found that in the case of the mr2 loom wires that do match-up from loom to loom are not neccesarily the same colour, which means you need a wiring diagram for both model engines and/or you need to trace every single wire with a multi meter. This is the only part of the conversion I didn't do myself as it is very time consuming and far too complex for my small brain to comprehend. My advice is to take it to a competent auto electrician, and if you can, get hold of a wiring diagram in advance. The re-wiring cost me nearly $600 if you need a reference of cost. Good luck

[sideshow]

mr2s ar episs easy just like doin a 202 in a hq heheh

ive wired up many 3sgte in celicas its not hard job for me but still takes me about 8 hours to wire one up and make it look std and cut everything not needed out

pay me the right money and ill come to melb and do it heheheehehe

[terryo]

I've done these. they are not fun. the Gen 3 3SGTE uses totally different body loom plugs so swapping the loom does not fix the problem. i suggest you lay the gen 2 harness into the gen 3 engine. you will need to swap injector plugs, oxy sensor & plug (dont cut this plug off)
Ignore TVIS and cold start injector wiring as they dont exist on gen 3. If throttle plug is dfferent on your models, just swap the whole unit.