Because of the instability issues with the 1JZ stock EMS it is a nice upgrade to switch to a 2JZ-GTE EMS.

Almost or all sensors on the 1JZ are identical to those on the 2JZ as long as you have a JDM engine like the ones that come from soarers (jzz30) and chasers (jzx90). Those ECU’s are map (Manifold Absolute Pressure) based instead of the MAF sensors used on USDM and European spec supras.
You will be looking for a JDM 2JZ ecu from an Aristo JZS147¬† (That’s the one without VVT-i).

There are two differences you have to overcome:

1) The Aristo 2jz-gte engine has 440cc injectors where the 1jz uses 380cc. You will have to replace the 1JZ injectors with 440cc 2JZ injectors or bigger.
2) The 2JZ-GTE rocks sequential injection. The 1JZ uses batch injection, and you will have to convert that yourself.
3) The plugs are different. I bought a conversion harness from Dr. Tweak (Tweaked performance) to be able to use the 2JZ ECU. I bought the one with 6 flying leads. I extended the leads and lead each one to the corresponding injector. At each injector, cut the right wire and cap off the cut wire. Then solder on the corresponding flying lead.

For clear instructions see: http://www.shoarmateam.nl/upload/JZZ30/1jzgte%20injector%20rewire%20for%202jzte%20ecu.xlsx

Just to be clear about this: Fiddling with your EMS can be harzadous if you don’t know what you’re doing. Any damage done is your own responsibility, not mine! Be carefull.

Okay, sounds expensive. What is it that I’m getting out of this?

You will be upgrading to:
– Better timing maps
– Better fuel compensation for bigger injectors up to 720cc
– Lower rev limit¬† 6800 instead of 7200 (not so much an upgrade…)
– Much much more stability and peace of mind. The 1JZ ECU will take a crap on you. The 2JZ ecu will not do that any time soon.
– You enabled upgrades to a JZA80 PnP aftermarket ECU like the AEM or ProEFI.

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