Fuzzy

I have a 1986 4runner that I swapped the engine with a 1989 4 runner and wiring harness everything matches up to the engine control box except two plugs , is there a wiring harness adapter for these two different year plugs

Hadmatt54

You can't run the 89 motor harness on the 86 4Runner. The 86 motor has low impedence injectors and a resistor pack to limit the current to those injectors. This injector circuit is known as a voltage controlled driver circuit. The resistor pack is part of the body harness and is located on the passenger inner fender. In mid 88 toyota changed the 22re to high impedence injectors without a resistor pack. So your 89 donor engine is this type. The injector driver circuit in these is known as a current controlled driver circuit.
The 86 ECU is not set up to control the injectors in the 89 and the 89 ecu cannot control the injectors in the 86. You have 2 choices to make this truck run right. (1)Transfer the wiring harness, sensors and injectors from your 86 motor to the newer 89 motor and run everything like it is a stock 86 or (2) leave the engine alone and transfer the ECU and complete body harness from an 89 donor to your truck and run it like a stock 89.
Some guys will tell you just get rid of the resistor in the body harness, plug in the 89 ECU and you are good to go... that is half true, but you have already discovered that 2 harness plugs don't match up between the years. Without wiring diagrams for both years and the ability to trace out automotive circuits and know exactly what the function of those circuits may be... it will be a really hard task to get this truck running right.
The easiest way to do this is option #1.
Good Luck!

Aido

I ran into a similar problem with my '86 4runner. When I purchased the truck it had an '86 22re block, ecu, sporting a '89 intake and '89 injectors. The truck seems to run regardless of the difference in the resistance differences. The resistor pack is hooked up and working. I put 30,000 kms on it since I've owned it, without a problem. Now I'm swapping in a fresh 22re, (as the old has 500,000kms on it) and am wondering if I should bypass the resistor? I have a harness and ecu from an '89. I talked to a Toyota tech guy at a local dealer and he advised me to bypass the resistor and run the '89 ecu as I'm having problems finding a good '86 harness and injectors. As for the 2 non matching connectors on the wiring harness, I've traced each wire out and spliced in the connectors from my '86 harness to match the truck harness. I can post the wiring diagram if anybody needs it.

slobrorunner

Sorry to revive an old thread, but I have a very similar question...
I recently rolled my 89 first gen 4runner with a 22re backed with an auto. I stripped the entire thing down and kept everything and scrapped the body and frame.
This week, a fully loaded 86 sr5 came up for sale without the motor. The guy built the 22re and was disappointed in how slow it still was, so he pulled it and was going to do a 3rz swap but lost interest.
The truck does not have an engine harness, but I have my old harness and ecu. Can I just replace the ecu and harness with my old 22re one and run it? Or would I have to tear apart the dash to get to the body harness and change the entire thing? Also, this 4runner is a 5 speed so if I used my ecu I would just have to jump the NSS to get it to start and run correctly correct?

Will I have a problem with Smog if I just tried to smog it with the 89? Or do I have to get it Ref'd to get it to pass here in California.

Thanks,
Joe

And just cause no one likes a thread without pictures:




My 22re


The 86 I'm looking to buy:

Little Elger

Will there be any power difference in using the 86 injectors in the 89 engine. How tough is it to pull the 89 wiring harness? I am swapping 89'22re into a 86 , I have both harness in the trucks just need to know the easiest or best route to take.

Little Elger

What sensors from 86 would you have to swap to the 89

Greg.Angell

Any chance there is anyone that has been able to figure out this problem of the 89 to 86 engine swap with regards to the wiring harness?
Any info would be great, I'm running into this problem now

old87yota

The easiest thing to do is to is to just to use the long block donor engine, and use all of your existing sensors, manifolds, injectors, etc. from your old engine and bolt them up to the donor engine.

I assume you are using 22R or 22R-E engines.

Greg.Angell

Ya it's the 22re engine. I was able to rework a bunch of the wiring following them and managing to hook them up the same way. Truck is running now, only thing i seem to have not done properly was the engine diagnostics wiring. So check engine light is always on now, and I'm not sure i can check or adjust the timing.