1jz in mx83

[mojo_type]

ok so ive got it all in and up to wiring and im kinda stuck

the problem-
the 22 pin ecu connector in the mx83 cressida i need to repin so i can plug it into the jzx81 ecu

the answer ?
ive made this pinout diagram, top image is the cressida plug, middle is the jzx81 plug and the bottom
is what it should look like if i mate the two in order to get the jzx81 ecu to work with the cressida gear
and im pretty sure it should work, in being pretty sure ive therefore cast doubt on myself.

Can anyone confirm deny this should be fine ?
its a 1989 MX83 GLX Cressida (analogue speedo) and ive put a 1990(could be 91) JZX81 Cresta engine and gearbox in it.

Cheers
Jay

[CrUZida]

Have you checked Flyen's diagrams on Thermactor?

[Adam_Cressi]

Have you checked Flyen's diagrams on Thermactor?

good point looked at them last nite, just out of boredom..

[mojo_type]

yeah ive worked out my pinouts from his and another source i had, he doesnt have the aircon
clutch though and i added "L1", "L2" and "L3" which he didnt have on the pinout.

just as its a popular conversion i was sure someone else has done it and worked it out
and could confirm ive worked it out correctly too instead of just going on flyens rough diagrams
as every other aspect of this conversion is easily found on the net but this one ecu plug i cant seem confirm
(no offence if you read this flyen )

[Mos]

This should be fine. Repinning and adding pins is a perfectly valid solution.
L1, L2, L3 normally isn't used, so you shouldn't need it.
ELS and STP are available on the larger of the grey plugs - doesn't hurt to have them.
OD2 is your overdrive off switch - you might want that.
A/C M (or ACMG) is cute but not necessary (there's a thread about it).
If you leave FPR disconnected make sure you short out the fuel pump resistor on the driver's side strut tower.
Mos.

[CrUZida]

Mos, any idea what L1, L2 and L3 are for?

I know they are only there for the engine ecu to talk to a separate tranny ecu (ie, any car with integrated auto/engine ecu doesn't have them), but I don't really know what they are for.

[mojo_type]

mos your a god

so i will need to find the od2 switch lead or is it just called something else on the mx83 side
i will grab els and stp from the other grey plug
and the fpr can i connect it at the 22pin or do i need to short it out under the bonnet ?
not quite with ya on the fpr

thanks heaps i really appreciate the help and the descriptions of the pins

[Mos]

Mos, any idea what L1, L2 and L3 are for?
I know they are only there for the engine ecu to talk to a separate tranny ecu (ie, any car with integrated auto/engine ecu doesn't have them), but I don't really know what they are for.

They are a binary representation of the throttle position. Can't remember where I read that, but it was either toyota or autoshop literature.

Mos.

[Draven]

Mos - resident toymods wiring guru.

[CrUZida]

Ahh, so no L1,L2,L3 outputs, mean no kickdown?

I was just thinking of using a manual ECU and an MX83 ECT ecu to run a motor and gbox.

I guess I can get rid of that thought.

[Mos]

mos your a god

That's what she said!!

so i will need to find the od2 switch lead or is it just called something else on the mx83 side

It's on the MX83 plug you posted, although sometimes it's OD0 - it's a switch to ground, with the O/D Off light pulling to 12V - search for a thread on A/C and O/D 1JZ, I even posted diagrams (but can't find the thread right now and being lazy).

i will grab els and stp from the other grey plug
and the fpr can i connect it at the 22pin or do i need to short it out under the bonnet ? not quite with ya on the fpr

FPR is the fuel pump relay, which switches the fuel pump from low speed (~9V) operation to full speed operation. There is a resistor on the D/S strut tower which provides the drop for the low speed. The FPR pin controls the FPR relay (D/S kick panel fuse box) that bypasses this resistor to run the fuel pump at full speed. If you don't use the FPR pin, the resistor will be in the circuit all the time, running the pump at low speed and almost certainly causing a leanout due to insufficient fuel delivery.
IIRC there is a FPR pin somewhere on the 1JZ ECU but I prefer to remove the resistor completely - easiest way is to permanently short out the two wires that go to the resistor on the strut tower (they can be cut shorter and taped back into the loom to remove any evidence of their existence ).

thanks heaps i really appreciate the help and the descriptions of the pins

No worries
Mos.

[Mos]

Ahh, so no L1,L2,L3 outputs, mean no kickdown?

Hmm never thought about that, but if you're using an external ECT ecu without a kick down input then I would conclude the same.
A 3 bit ADC shouldn't be too hard to implement?

I was just thinking of using a manual ECU and an MX83 ECT ecu to run a motor and gbox.
I guess I can get rid of that thought.

You mean MX73 ECT ecu?
You know it may be possible to use an ECU that has L123 outputs, input the throttle position, and hope that it spits out L123 for the ECT ecu (but then you'd have 3 ecus, and you could probably just use the second aforementioned ecu to run the ECT directly....) But yeah, it doesn't look like it would be that straighforward...

Mos.

[CrUZida]

MX83's don't run ECT ECU's ??

MA70's do.

[CrUZida]

And Mos, get an avatar ffs

[mojo_type]

love ya work mos
very greatful
ill give it a go and see

ta
Jay