I have a complete engine out of a 98 4Runner w/auto trans. I installed it into 94 4Runner with manual trans. w/4x4. I know I have to get a wiring harness for a 5vzfe engine with 4x4 and manual trans. Now comes the tricky part. I have already purchased the computer I need for the set up I have. Is there any way that I can tell what wiring harness I need by looking on my new computer.

 

I believe you need the computer (ECU) from the MT vehicle from the same approximate years(??). Are you certain you have a MT ECU? There is a code on the side of the ECU that determines what harness is needed.

You have already installed the engine in your 94 without the engine wiring harness? It might be a bitch to install this while the engine is installed. Not saying it can't be done though. Are you planning to modify the harness to work in your 94 or purchase a premade harness? Either way Mike @ ORS would steer you in the right direction.

I am currently in the middle of a 3.4L swap in my 94 using a 98/3.4/MT. I probably have had my engine in and out 5 times test fitting stuff before I finally got it in for good. I have only exhaust to run before it's finished.

 

On the ecu the factory label says 5vzfe 4x4. I called Toyota and all they could tell me is that they need the VIN# for the wiring harness. I have no idea what the vehicle is that it came out of. I am using an engine out of a 98 4Runner with automatic. I do have the wiring harness though for the automatic even though it wont work for me. I have resentley came accross a wiring harness and ecu (out of same vehicle) for a 99 4Runner for $275.
So far I have the power steering, fuctional clutch, fuel lines, A/c, installed. The two biggest things are left, exhaust and wiring. Let me know what you are doing with your exhaust. I was hopefully going to have a local guy who makes custom headers connect the 5vzfe manifolds to the existing pipe.

 

I am going to take a look at some diagrams to see if I can tackle it, I also have some friends who are good with wiring so at this point I dont know which way I am going to go.

 

Here is one of the best threads here on YT with lots of links that should help with your swap.
https://www.yotatech.com/forums/show...light=3.4+swap