1JZ auto to manual swap questions

afracer

New Member
Sep 1, 2007
51
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0
Abilene, TX
Alright guys, I know a lot of you probably don't have experience with a Mark II/Cressida, but mechanically they are almost identical to the JZA70/Mark III Supra. I have a 1990 Cressida with a JZX81 1JZGTE/auto swap done by Grip Industries in Florida. I've driven it for over a year now and it's been a GREAT car, but it's getting to be time to do some more serious work to it.

Those of you that don't know, the JZA70 and JZX81 use the same ECUs. clutch pedal/master cylinder, and just about everything else. So, I've got an R154 for it and plan on doing a manual transmission swap. I've got clutch and brake pedals from a Mark III, master cylinder, driveshaft, and I just bought a Mine's ECU for a 5 speed JZA70 for it.

I know I can just bypass the neutral safety wires and keep running the auto ECU, but I'd rather upgrade and use the Mine's 5 speed ECU. Will I run into any problems using a 5 speed ECU on an automatic 1JZ wiring harness since I'm swapping the tranny out to be a 5 speed? I've heard/read and it makes sense that you can't use a 5 speed ECU while using an automatic transmission, but if I swap the car with a 5 speed and then use the 5 speed Mine's ECU it should be okay right? I know in my SR20's it really doesn't matter as I'm currently running a 5 speed blacktop ECU on a automatic converted to manual 240SX, but I'm not sure about Toyotas/1J's.

Yeah I know it seems backwards to buy the ECU before finding out if it'll even work or not, but I couldn't pass up the deal and I know that JZX81 and JZA70 have the same exact pin outs on the ECUs. If anyone can shed some light I'd be really grateful. I'm expecting to do the swap sometime in November/December and I guess I could run the auto ECU if I have to for a little while, but I'm hoping I can run the Mines and pick up even more power :biglaugh: and also because I plan on upgrading to a GT35R/550s/BC Cams/SAFC later on too. Cheers
 

Rich

tunin' tha beast
Jun 2, 2007
319
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the netherlands
It's not that difficult. An auto ecu and a manual ecu are the same engine wise. All an auto ecu has more is circuits to drive the auto gearbox.
When going to a manual gearbox, the only thing to alter is to by-pass the neutral-safety switch, you can keep using the auto ecu without any alterations or changing wiring.
So if all mechanical parts are installed and the neutral-safety switch is by-passed you can just plug in the Mines and it works.

Most likely the Mines is also tuned for 550's, take that into account with your set-up.
 

afracer

New Member
Sep 1, 2007
51
0
0
Abilene, TX
Yeah, thanks a lot. I figured that was the case but since I'm fairly new to Toyotas I wasn't too sure and I've read so many posts about using A/T wire harnesses and M/T harnesses with opposite ECUs and all that kind of stuff, so I didn't know what to think.

I have no idea what the Mine's is tuned for, but the guy who sold it to me said they ran it on a stock 1J just fine as well as larger injectors and HKS turbines just fine...so who knows?? I will put my Innovative wideband and thermocouple to use!