Hi,

I searched for this answer, as I know the answer may be out there, but I couldnt find it, so I apologize if this has been previously answered.
Donor 2002 4runner A/T. Recipient 90 4Runner 3.0 5sp M/T. MT ECUs are not easy to find without spending a ton of money, but I found one from a 1996 Tacoma 4X4 (89661-04220). I am hoping since I have the MT ECU my wiring harness challenge will be lessened, although apparently something changed in 1998 regarding the MT/ECU. How does this imperfect (according to ORS) ECU match affect wiring harness accommodations? I still want my tach, 4x4 light and else to work properly. I am not doing this myself, but I want to be informed, and I also want to get any needed parts before the shop starts in a week or so. I am hoping the answer I get will be that any harness adaptations are pretty straightforward, given that I may have already gotten halfway there.
My shop is good but doesnt specialize in 3.4 swaps, so any heads up I need to watch for regarding common shop shortcomings, feel free to share.

Thanks so much for the answers.

Thanks,

Charlie

 

Charlie your shop has it`s work cut out for this project.

Stated very simple if your using the ECM from a 1996 Tacoma .

Your engine harness needs to match that of the 96 Tacoma

It is much easier to repin the ECM you have the Engine harness for

In any case it comes down to having the EWD`s for all the vehicles your merging electrical parts from .

Doing one circuit at a time.

 

Thanks for your reply.

Anyone know where I can get a wiring diagram for a 2002 A/T donor to a 1990 M/T? I know there are a ton of posts about wiring, but there are a ton of variables, and I cant find this particular situation.

I dont have time to get an ORS conversion, as apparently they take a 2-3 weeks.

 

bbb industries has free wire diagrams on their website http://www.bbbind.com/free_tsb.html

 

Im doing a swap myself n cant find where to post. If i can find a 96 harness would it work with a 2000 3.4 engine?

 

It depends on whether it is 4x4 and AT or MT. Depending on that info, we then have to define "work with an engiine" specifically if you want your gauges to work, and whether you are OK with having the check engine light on, which can be the biggest challenge.

The best chance you have of getting a very accurate answer is checking with Mike at Off Road solutions. Call or e-mail him off of his website. He is super responsive. 99% chance he will know the answer, including caveats about gauges and check engine light. The answer can be counter intuitive to some degree: My donor vehicle is a 2002 4Runner, 4X2 AT. I am putting it into my 1990 4X4 MT. The best ECM for this situation, so that all my guages work with no check engine light is on? 2003 or 2004 4X4 MT. That makes sense, right? no, not. (My scenario reflects the fact that Mike at ORS is providing me the wiring harness conversion.) Anyway, if you want an accurate answer, contact Mike, but he needs to know the transmission info.

 

The 2000 is an auto n its going in my 91 3.0 5spd. I have the harness and ecm from the 00 but found a 96 3.4 ecm for a manual transmission. Il send him an email though.

 

no no no and no.
the harness of the 2002 is waaaaaaaay different including that the connectors for the ecu are shaped different and the pins are smaller. Even if you used the "long block" and found a matching harness/ecu. You need matching sensors and injectors to the ecu. In 2002 they started using partial throttle by wire, and no kickdown cable on the throttle body. They t-100 and tacoma used a different tps and throttle body than the 4runner. The 4runner harness also has the evap and rear 02 sensor in the engine harness where the tacoma and t-100 did not up till a certain year.

 

Its a 2000 with no wiring going to the throttle body. If i can swap the harness out for a 96 it makes my swap easier. No word from ors.

 

Having just finished my wiring harness, let me start by saying I feel your pain. Second, you should get yourself the EWDs directly from Toyota. I seem to have lost the link, but a little searching should turn it up. I did the two day for $15 deal and downloaded the full EWD for my year engine as well as some select diagrams for the previous year's engine and my recipient vehicle's diagrams. This made it a LOT easier.
As vital22re said, you've picked the wrong combo of engine, ECU, and chassis. Your best bet might be to buy a 95.5 - 01 throttle body (earlier is better) and put that on your engine. If you look hard enough, you should be able to find one for about $40 on craigslist. Make sure you get the wiring connectors for the TPS and IAC or you're up a different creek.
Next, you need to get connectors that will fit your ECM. AT ECU connectors are very different from MT ECU connectors, but the good news is your local stealership should be able to get them for you relatively inexpensively. Failing that you actually can buy them from Tyco or one of their distributors.
Lastly, you'll need to run some extra wires for the starter trigger, EVAP, AC idle up (if you want it to work), and maybe one or two other things. You'll also need to splice some wires and route a few things into or out of the chassis harnesses.
What you're trying to do isn't impossible, but it's going to take some work to make sense of the wiring diagrams. Check and double-check your work and then check it again and you should be fine.