traxxi2003

I need help with replacing the engine on my 97 TR4 with a 2000 JDM 5VZE. My original engine decided to throw a rod the other day, and it looks like the cheapest way to get my truck back on the road is by installing a JDM 5VZE. The question that I have is, since my truck is a 97, will I have some compatibility issues with the replacement engine harness and my ECM? I'm aware that I should install my original intake and accessories on to the new engine, but how about the injectors and the injector harness? Has anybody done an engine swap like mine that can answer my questions?
Thanks!

JasonYota

iTrader: (1)

Depending in where your current oil dipstick tube is you may have to drill one in the 2000 block.
I don't have any info about the wiring differences.

TheDurk

The ECU connections are wildly different '97 to '00, if US. Who knows about JDM? If the JDM did not come with an ECU, it will be much easier to adapt your existing harness to the engine. If it did, then it would take some research to decide whether to keep your existing ECU and harness, or go with the new ECU and harness. But I'm betting on wanting to keep your existing ECU AND harness. If you have emissions testing, changing ECU years will freak out the state computer. Adapting a harness to an ECU with that many years of difference is a non-starter in my book. Adapt the engine to the harness and vice-versa. Most of it is sensor wiring that doesn't change over the model years. See if the new knock harness (separate piece) fits the old engine harness, as yours is probably shot. It will fall apart if you try to switch it over. So take advantage of a new one.

That's my guess, but I would defer to someone who has done a JDM install, as I have not.

When you pull the old one, make a list of every connector you undo, and leave the harness on the truck. Then see what you have to do to marry those connectors to the new engine. If you can use the JDM sub-harnesses, do so.

SacRunner

I would remove EVERY thing that has a wire attached to it from the the JDM motor, and replace them with the equivalent part from your broken 97 motor.

There were a number of small subtle part changes in sensors over the years of the 3.4 and like TheDurk mentioned, that's just within the US market, the JDM market could be completely different. I'm sure most of the things are "close enough" that it may start up and run "ok" for a while but could eventually cause problems for you that will be a nightmare to diagnose.

Your 4Runner is a 97, your ECU is a 97, your ECU is expecting to see sensors and parts for a 97 and not a '00 JDM, so swap all the 97 electrical parts to the '00, and make sure to use your 97's engine wiring harness.

Use the JDM motor as just a mechanical replacement for your motor, keep all your old 97 electronics.

traxxi2003

Tanks you for all of your responses, but I still have one more question, that means I should also use the injector from my broken motor as well?

SacRunner

I would, Toyota changed the injectors sometime around 99-00 (if memory serves me right), maybe do a quick search to see if the new ones are compatible with the older ECUs but I would use the 97 injectors. I'm sure other's may have a little more insight than me, I've only dealt with 96 and 97 3.4s.

vital22re

iTrader: (2)

buy new intake manifold gaskets and just swap over your entire intake set, the lower plenum(bolts to heads), lower manifold, and upper manifold with throttle body. Swap over all the electronics. Even the exhaust manifolds will be different (atleast the one JDM motor I've used) While you are swapping the lower manifold, replace the knock sensor sub harness. Replace the valve cover seals, full timing set including the thermostat.
Or leave the lower intake plenum and swap over the sensors and fuel injectors. Just be careful you don't pinch any O rings.