using the stock computer and harness.. HELP!

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New Member
ontario, Canada
so here's what i am wondering
if i use the stock 1uzfe computer and harness and only change the transmission to manual leaving everythign else stock.. do i need that part of the harness?
I am able to get a harness from a local wrecker along with the computer.
I was thinking to cut the section that seems to go down to the transmission.
Is this a bad idea?
I am planning to use a 7mgte from a mk3 supra.
Will cutting this section of the computer cause problems?
please let me know as I'm hoping to put the engine in using only the stock computer for now.
Later down the road I will be looking for more power and tuning and also go the direction of building the motor. I was hoping to go turbo but I feel that a high compression buildup would suffice just fine.
I am putting this engine into my 1972 toyota corolla (much like the flea) only I'm building a car for turning and he's building one for straight lines.. Yes i could go with other engines.. but why.. this is something i've wanted to do for a little while now.. when I saw that the flea had done it i tried very hard to stay away from the idea.. but finally i've stopped lying to myself and the idea is coming together..
will this work?
has anyone done it?
is cutting the harness a bad idea as i will be keeping everything stock for a very long time?!
let me know
cant wait to read the replies


New Member
Australia Gold Coast
I am running 1uz stock ecu with manual conversion. Yes you dont need any of the gearbox wiring. I dont understand your post thou, your not very clear. How does the 7mgte come into it with 1uz ecu and wiring harness???


New Member
Christchurch, New Zealand
You will need speed sensors and things depending on what model of ECU you have - I'd hold off cutting the wires until you absolutely have to. Do a search on your ECU numbers and see what comes up.



Super Moderator
Staff member
Sydney, Australia
If you're running the 1UZ engine with the manual trans from a 7MGE equiped Supra you won't need speed sensors for this conversion as you won't be using traction control or the Auto trans.

I'd cut the loom without any reservations.


New Member
ontario, Canada
i'll be using the 7mgte transmission.. the r154 i believe it's called?
am i right in assuming that what i'll be cutting is the transmissoin part of the wiring harness?
this part is at about the end of the intake manifold and goes directly downwards from what i was able to tell.. i'll be going back to the wreckers tomorrow to try and take out basically everythign that's got a wire attached to it pertaining to the engine
insight is helpful
as for this speed sensor.. is this something i'm able to use from the auto trans onto the manual transmission?
i was hoping to put in a set of autometer guages so that i'm able to monitor everything, but i figure that they will all be mechanical as well.. i trust the mechanical things and they come with pretty well all the hardware to mount them onto anything.. from what i've been told i'm going to have a real fun time adapting an electric speedometer to that transmission or for that matter electric anything to this car, they dont seem to make a speedometer gear that i'm able to put into a toyota transmission.. or at least that's what the parts guy i used found out for me.. dunno how accurate that is.. but so far that's what i've been told
AAAAAnyhow.. the computer doesnt require any trickery to get out the harness then?
Cutting it is not something i shoudl worry about?
lots of people say cut.. a few say dont cut.. i see both sides of the story.. i absolutely have to jump on this purchase though as it's the cheapest thing i've ever been quoted for at this wrecker.. they always seem to want a million dollars for everything.. this was a little bit of a relief..
so everything in the engine bay with electrical wires is what i figure i'm going to be tearing out.. anyone saying anything different?
also.. relays.. which ones to take and which ones to leave?!
pictures are helpful if you have them
if not.. i'll tyr to make do with your descriptions
keep it coming!
very helpful so far!
giving me the confidence to move foreward anyway!

nearly forgot!
ecu's.. was there a difference between the ones found on the sc400's and the ls400's?
were the years different in terms of ecu?
is that why from generation to generation there are different horsepower ratings or is that all just the head?
that's somethign i've been really wondering


Active Member
the only wires u need for a manual gbox are

3 speedo wires if u have electronic speedo

2 reverse switch wires

if u have abs you might need a special electronic converter box so that you can
have a speed signal goin to the abs ecu

what is the car that the 1uz is fitted to
does it have abs
is it cable or electric speedo

from all the 1uzs i have wired up
ls400 ecus are totally different to sc400 ecus that come from japan


New Member
ontario, Canada
i'm going to be using this engine in my 72 corolla.. much like my buddy the flea!
i will be using the r154 tranny and from there a couple things change up from his car.. but pretty much the same thing.. only i'm going to try to keep it stock for the first little while.. cant afford anything else really.. thanks for the reply though!
appreciate it!