1991 7MGTE to 1987 7MGTE
 

I have a problem. I work at a shop and we have an interesting combination of elements here. I have a 1991 Supra Turbo with an engine MT and ENGINE wire harness that came out of a 1987. THe owner gave up on trying to figure this out, and now its in our lap. I'm wondering if anyone can give me some advice. I'm seeing from difference in the wiring diagrams that there are major differences all around as far as routing and pin configurations. First of all, does anyone know if it will work out? Secondly does anyone know if the ECU is ok to use- mine has the part# 89661-14260 (which from other forums shows to be a 1989 part number which came with the 1991 car). What I need to do is make it run. There are a couple connectors under the dash for the ECU harness and engine harness that are different (some wires at different pins, some not even there on one side or too many on the other). I have a set of connectors to start switching stuff over, but there's missing wires or extra wires that between both diagrams show them going different ways. I'm really frustrated at this thing, and don't even know if it will work. Anything you can advise would be appreciated.:barf:

Just tossing this out there.. I have only a slight knowledge of the actual mechanics of cars. Is it possible that the car got its wire harness from japan and its just different than a US one? Do you know if the 1991 engine was actually a swap from the original? those would be my 2 guesses at it. I would have thought they where :yum:interchangeable:yum:.. Is this 87 7MGTE from japan?

Not too sure, but almost positive....
 

The engine that blew came with the car and it was a US car, and the engine that went in was a scrapped engine from a boneyard which came out of an 87 US car (as far as the owner knows). I'm looking around for wire harnesses and possibly an ECU, but I don't want to buy them without needing to.:stickpoke

Did they swap anything else over from the 87 Supra? Such as the fuel injector resistor packs on the firewall? I'm assuming that since the 87 harness is still connected that they kept the 87 fuel injectors and fuel rail...

If I was in your situation, I'd get the fuel injectors and wire harness from a 89+ turbo supra. That way the factory gauges will operate properly and it should just be plug and play. If a wire harness is hard to find, you can get a 87 ECU, 87-88 Gauge cluster + dash harness, the resistor packs for the fuel injectors, and maybe some other odds and ends to get it running right.

I'm sure it's possible to rewire the connectors on the wiring harness to make it connect to the ECU properly, but you will still need to address the fuel injectors. pre89 7MGTE's use low impedance injectors, whereas 89+ used high impedance injectors (I think that's right, might be the other way around though; trying to recall from memory).

Anyway, help this gets you pointed in the right direction.

Unnngh
 

Sounds like a real headache, Glad I'm not attempting it. By the time I had it figured out and picked enough brains I would have wasted more time than the car was worth.... But that's just me.

All years 7M-GTE used low impedance injectors. Only 7M-GE's saw that change.

same project
 

i have a 91 supra and it is a na, and im at the same problem, well im building it. i bought an 88 supra and i found out the harness is different and all. if u can what u figure out post so i can go over the info so i can then save time myself.. i know it is a pain in the rear...

god thats the 5th time i seen that link end a thread..

Thought blake would need it so don't go buying stuff that's not compatible with one of his 2 supras..

lol, that's funny you have seen the link ho'd out like that..

seen it befor
 

the problem im having is the dash connection's for the ecu i just need to know how to wire it in, im also looking into getting a 90-92 ecu for the 7mgte, m/t. this way i could use it with my 91 harness, but if i guess right there will be connector's on the 88 block and head that wont work with the 91 harness... im stuck in a dark place... lol... HELP :dunno:

Buy another harness??

good luck.

i am considering useing my 91na harness
 

no not buying another i have a whole nother motor blown... but will a 91 na harness wirk with a 91 turbo ecu and a 88 turbo block and head? i will be dyno tuneing it since i have 60+ wiseco pistion's, eagle rod's, shaved and polished block and shaved head and the whole ten with the block and head the 1uz-fe afm and 550 cc injector's 3inch intercooler 3 inch exsoust, a t67 turbo, t4 manafold, 50mm wastegate, 2mm headgasket, arp head stud's and who know's what elce, to much... im buying a coulpe of part's still. but im mostly there that's why im asking what all you guy's know befor i try to finish. these are the combonation's i can try, i have the 88 turbo ecu motor and r-154 tran's, i have the 91 na with motor ecu and w58 or what ever the tran's are both 5-speed, and both have compleat wire harness, or looking to buy an 91 or 90-92 turbo ecu m/t , what will be the simplest, oh mind the fact's one thing not changing is the 91 dash connecetion, and the 88 turbo block, so...

Err, I don't have the time right now but I am sure that in the link I supplied it states what ecu will or wont work with 86.5-88 ecu etc...

Simalar Project
 

Here is my predicament..... I have an 86.6 Body, and a 90 GTE engine. Do I use the existing harness on the 90 GTE engine and couple it to the 90 ECU? OR... do I swap in an 88 GTE under-dash harness and cluster, then use an 88 GTE engine harness and ECU. I have all the wiring from 3 different Supras, and clusters from 86.5, 88 GTE, and 90 GTE. Will I have swap in a GTE harness to the engine bay/chassis? I just want the easiest way to achieve working telemitry and functionality.

If I understand you correctly I think it would be easiest to us the 90 stuff to go with the 90 stuff rather than swapping this and that out.. Just seems easier to me. Besides that.. THREAD JACK!

88 ECU and engine harness and GTE tachometer would probably be the easiest route, then you shouldn't have to worry about the dash harness.