I have an 86 4runner 22re and I have the new to me 89 22re motor installed .

I only have the 89 motor , 89 motor harness ( with the other end of the harness from donor vehicle) and 89 ecu .

I've heard conflicting information on this swap and compatibility of the electrical components.

I know this swap has been done a hundred times. can anyone offer any advice?

will I be further ahead by tearing the dash apart to install an 89 body harness or can I mate these two together?

 

Both of the forward harnesses are different, so dash cowl and engine harness are needed.

 

so both harnesses are needed from an 89(dash and engine). the dash harness will hook up to the components of the 86 chassis?( speedo heating controls etc?

 

You might be able to get away with repinning the N# connectors, where the engine harness connects. But you need to do the research. For example after 88 the diagnostics all moved to the battery junction block area into a single plug (M) from individual plugs on the air box side..

It's much less work to swap the earlier sensors onto the later longblock if you have your original harness.

You'll have to poke around for the details regarding the aux air (idle) valve to go that route also.

.. The answer to your direct question is from what I recall the signal levels (voltages) are compatible between the two but things like the combination meter probably moved some pin location.

 

I'm also trying to do the same thing here, swap an 89 into my 86 4 runner. I just can't seem to find much information about what exactly could be done without having to rip the whole wiring harness from the dash of both 89/86 trucker

There was a post from awhile back were someone said they did it, but left zero details lol