New old member....A650E to A750F Question

[Tacoma_Kyle]

Been on here a long time. Started a 1UZ 77 Celica 5 years ago. Grad'd college, couldn't finish it because it was a rolling chassis and rapidly moved from OR to NY. While I accomplished a lot the car wasn't worth paying 1500 to ship over. It's sitting in the driveway of my parents place in NorCal, lol. Going to part it when I go back there for a few weeks and scrap the chassis this summer. Such is life. I took some lessons in planning and execution in the process.

Now I'm somewhat well off for a single guy. Have a 2 car garage, got a 06 IS350 last year. Not new but I love that car. Then I have my 99 Tacoma, which I rolled a year and a half ago, lol. Upside down in snow, roof is beat up but it alive and kicking just like when I bought it in 04. Using the ~2k tax return to buy a cab from a guy in AZ from a 01-04 Tacoma and getting it shipped up here so I can have a straight, matching color cab again. THats NOT exposed to this shit salt up here.

And being that my good-ol truck has about 215k, yeah I'm starting to think about a replacement engine. And have a bit of swapping experience in terms of compatibility problems.

So I have a few questions/requests for advise. TO help me to decide if I want to keep my 5VZ and rebuild it or fulfill my V8 (or 4.0 V6 I am considering) desire. My Tacoma is a 4wd and I will keep it 4wd.

•I will run OEM engine management.
•I will run a auto tranny.

Engines considered: 2UZ or 1UZ, VVTi only. The non-VVTi are simply not desirable enough on a stock ECU. 3UZ costs substantially more, not worth it. I lean toward the 1UZ because of cheap, low milage JDM engines. And having a aluminum block, 6500rpm redline.

QUESTIONS/ADVISE Requested
•THe US VVTi 2UZ's came with A750F's (4wd). The US VVTi 1UZ's came with A650E's. Both are 5 speed. This of course wouldn't be a problem if I went 2UZ because it came with it. So anyone know compatibility in A7*** and A6*** transmissions on stock wiring?
•OBD2 is a USA thing and I want to keep it. I dont know how similar the overseas models are and if JDM EDU's codes are the same as the US models. Of course I could use a US ECU, but then I'd probably have to buy a US engine or harness. I've read of significant differences found between US and JDM harnesses/plugs/sensors. But that was mostly non-VVTi 1UZ's, it may have changed.
•Engine immobilizer. I could probably find a ECU/ignition/immo unit from a yard here, but it's be a PITA. THere are a few board members here that know what wires to cross in the ECU to bypass it, correct? To my knowledge, it's not a 'publicly' know DIY, yet? lol Or is it?


Thanks for reading my book! I am most interested on the transmission compatibility. If someone has some reason to recommend a 2UZ over a 1UZ, feel free, I am all ears. I just want to keep the weight down on my truck and like 1000 rpm extra.

 

[George_R]

All VVTi 1UZ's have modern-style diagnostic capability. From 1999 LS400 / Celsior comparison I know that the LS400 have a bit more things shown in its data stream. My diagnostic software (both Toyota original and enthusiast-written ones) make no differense reading common diagnostic data from either LS400 or UCF20.

Don't forget about the 180kph limit on JDM ECUs. It can be disabled by different means though.

Regarding immo stuff, yes the immo can be bypassed. It's not a commonly-known DIY for a number of reasons. The most important being that you must use some emulator to bypass it, there's no magic code you can put into ECU memory to disable the immo. If I (or someone else) publish any details regarding emulator firmware, schematic diagram and so on, a generic end-user would eventually get a poor (or a good) copy of the initial design from someone else, but he still would not be able to build the device on his own

 

[Tacoma_Kyle]

Yes, I have read about your success in cracking it, so to speak. I read about someone else, but dont recall the name. I recall you do it for 150 USD plus shipping? Saw that somewhere last month.

In a 4wd Tacoma, hah I dont need to be hitting 180 km/hr. 130 is scary enough in it stock.

 

[George_R]

Yes that's correct, plus time and shipping cost
In a 4wd Tacoma, you'll likely hit the limit at your scary 130 kph due to gearing. I run 205|60|15 wheels with 4.1 rear diff ratio and the limit is somewhere near 140- 150 kph

 

[Tacoma_Kyle]

George do you happen to know how compatible the US ECU's are with Japanese harnesses? I suspect they are not plug and play, but I think it is worth asking someone more knowledgable than I.

Thanks for your assistance.

 

[George_R]

Talking of vvti, LS400 ECU is pretty much pnp for UCF20/21 engine and vice versa. UZS15x (2wd,vvti) is compatible too. There may be some minor issues like UCF20 having a hydro fan, and throws error if hydro fan sensor/solenoid are not connected, but that's fixable and these error codes do not affect driveability.

Emissions wise, all these cars have 4 O2 sensors and provisions to connect charcoal canister. LS400 has tank pressure sensor in addition, but up to my experience the lack of the sensor does not affect driveability in LS400 and newer Toyota engines like ones from LS430, IS250

In addition, I believe that auto transmission is set differently for JDM and USDM. JDM is more sluggish and usually hesitates a lot, struggling to change a couple ranges down when flooring the car. I happened to use an USDM engine only twice (1uz and 3uz, both were from imported cars that ran well before been wrecked) so it may be only the matter of my feeling and engine condition.

 

[Tacoma_Kyle]

Ok. Thanks for the info all around. You can do VVTi 2UZ ecu's as well, correct?

 

[George_R]

Sure I do. I also plan to begin working with newer engines like the UR series by this summer

 

[Tacoma_Kyle]

Ok, thanks George. I'll get hold of you this summer if I need your assistance.

 

[Tacoma_Kyle]

And for what is worth to anyone else, I read a bit of Toyota A650E and A750E/F material, it doesn't seem you could just splice connectors over. While similar in some respects, the cross sections appear significantly different. To the best of my minimal knowledge on A/T's, the different number of brake valve solenoids and varying functions of shift solenoids between the two transmissions does not inspire confidence in using a A750 with A650E management from a stock ECU. Too bad too, because I like the lower top gear of the A650E.