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LJ78 to 1kzte conversion

Ash Awbery

Active Member
Mar 17, 2013
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So last summer my wife was using my LJ78 as a run around while we found her a new car (in the end we stupidly got her a Discovery 4 but that is a whole story on its own!) anyway she was driving and didn’t notice the temperature gauge go through the roof, meaning the 2LT was toast…

Why Toyota ever put a 2.4 litre engine in a LJ70 let alone a LJ78 baffles me!

So it’s time for something bigger. I’m no stranger to engine conversions as I put a bulletproof Daihatsu 2.8td engine in my LJ70, but the LJ78 has the added complication of an automatic transmission which I do want to keep so I have decided to go for a 1kz engine because with the right bell housing it will bolt right up to my gearbox.
To add another complication the engine and transmission in an LJ78 share the same ECU and one cannot run without the other… I have searched all the usual places and cannot find a completed thread where someone has done the conversion, I have spoken to a couple of people who have gone various different routes, so I am hoping to put a build thread together that actually gets finished! (Famous last words)

I narrowly missed out on a KZJ78 which had been badly made into a pick up (my wife was literally on the delivery suite giving birth to my daughter) this would have had everything I needed for the conversion. But it was not meant to be, so I have now bought a Hilux Surf with a 1KZTE and auto trans. I have the whole truck so my first plan is to swap out the 2LTE with the 1KZ (using the surf bell housing and torque converter) and I will see if LJ78 management will run the 1KZTE.

If this doesn’t work I have a few back up ideas to try:

1. Build a hybrid 2LTE/1KZTE pump - if that’s even possible?

2. Use the wiring harness and management from the surf and transplant it into my LJ78

3. Fit the 4M40 Mitsubishi manual pump I have to my 1KZ and use an aftermarket gearbox controller.

I am really hoping because I’m starting with ‘the right engine and gearbox’ the conversion will be straight forward ish…

Oh one final thing that will strike fear into anyone who has use a complete vehicle as a donor, I’m taking the surf to wales off roading at the end of this month because there is no way I would have the LJ78 ready in time, I could have taken the LJ70 but that’s not been on the road for a few years… luckily I hate the seat position of the surf so there is no danger of me falling in love with it… only the engine!

Watch this space.