240harrier

Sorry to bring up such an old thread but since I'm interested in swapping to 3GRFSE from 4GRFSE, any change need to be done on the transmission? Such as stronger clutch I suppose? Would the clutch from 2IS350 (or from 3GS350) be a direct replacement?
The auto transmissions between the two is exactly the same..

My car is Mark X GRX130 auto it is a mirror of 3IS250 and shares the same parts with 2IS250 except some few minors..

2013FSport

iTrader: (2)

I read through 80% of this thread and no one mentions looking at the long term fuel trims and/or STFT for that matter. This is a huge deal when doing swaps as the ECU can only deviate from the fuel map so far before it can't compensate any more per the fuel map. This would show up here and the cooked pistons from going lean would be there on display alerting there is trouble brewing. It sounds like the soul missing ingredient was fuel delivery correction and perhaps tweaks to the ignition map.

If someone does the swap and there is no way to bring the engines original ecu over, look at the fuel trims and they may tell the story when they consistently read 18 - 20%... That means the map needs adjusted. Yes the engine will run, but when under load and lean it will shorten its life.

Good luck...

PAVGR

iTrader: (2)

You are right buddy.I have the LMS sc kit and everybody said that the ECU can handle the extra power but that s not true!The car is running great until 4000 RPM.After that is getting lean and up to 6750RPM it s getting super lean!I ve learned this the hard way and changed my engine last summer.The car during my summer trip melted a spark plug and burned one valve.I ve send my ECU to OVtuning and the problem is now solved!The truth is that the car didn't make more power after the tunning (270hp) but it's running great and it's certainly doesn't get lean!I just returned from my summer vacations and after 2000 km I can say that my AEM AFR gauge is swowing great numbers in all RPMs especially after 4000 to 6750.I pushed the car but it responds great after the tunning!I do consider this swap myself and I ve already contacted Mathew from OVtunning and he told me that the ECU have enough fuel to run both 3GR engine and my sc kit so I do believe that this swap can be done but NEEDS a tune with or without an sc kit.

pepos

Dyno differences from the swap 4GR-FSE to 3GR-FSE.
Near to 40 BHP more.

Mattyc007

hi everyone, i am 1 day into doing this swap on my 2006 is, i havn’t hit any major hurdles yet 🤞,
i will be lifting the old engine and box out tomorrow as the engine had a small noise that im not overstruck on hearing and thought this would be an ideal time to step up to the 3L.
i see what people are saying about the ecu not having enough scope to run the 3gr but i was also under the impression that our ecus wasn’t tunable or am i wrong, i have the engine ecu that came with my 3gr engine and im contemplating (once the engine is all back in) at hooking up the 3gr ecu, can anyone tell me why i shouldn't.
sorry to revive an old thread im just looking for any ideas.
TIA

PAVGR

iTrader: (2)

I m curious to see if it's a direct bolt on.Let us now the results.Good luck buddy.

Jeff Lange

iTrader: (1)

You're doing a 3GR-FSE from a 2006 GS300 Automatic into an IS250 Automatic I assume? Likely no downsides to trying the 3GR ECU, though I would double check the pinout first. Worst case scenario you may have either immobilizer issues (unlikely), or ABS/VSC issues (less unlikely).

My suggestion is if you get it in and after handshaking the engine ECU with the immobilizer, don't do a zero-point calibration as the ABS ECU will attempt to pull parameters from the engine ECU and it may cause issues. It also may be totally fine though, so your mileage may vary, haha.

Good luck, keep us updated!

Jeff

Mattyc007

Yes my car is an auto and im refitting the auto box,
my engine has covered 167,000 mile, near full lexus history, the engine that is going in has covered 75,000 so im hoping if the ecu does run the engine etc that my mileage doesn’t change to the new ecu.
i cant see the pinouts being different but you never know i guess, last thing i want to do is go to all this hassle and then something goes bang,

Thannp

Just throw this out in the air

does anyone know if this idea is possible?

Creating a 2.5GR by using the 4GRhead+2GRbottom.

and using 4gr ECU with a tune to fix fuel map parameter to run the engine.

this way we dont have to mess with the transmission/driveshaft/rear diff if we do the swap on 250.

i have both engine laying around. Could be a fun project?

Mattyc007

Swap was completed a few days back but could not get any coolant delivered 😩 as toyota are on lockdown.
so yesterday i filled it with halfords pink long life, should be ok for now.
fitted my modded front headlights and 2015 style bumper this morning and took the car around the block a few times to get it all up to temp
It all seems fine apart from some funky smells i think is just oil burning off the exhausts etc.
ive not really give it much stick yet as i need to top up my auto box as i lost a little fluid, also now on order from toyota.

i have decided to run with my standard ecu for now just to get some miles on the engine etc
but i will also be doing some live data with my el cheepo obd scanner just to check what sort of fuel trims im getting ( and then figure out what they mean)

i can 100% guarantee this is a straight forward swap
i have done this on my own with a standard halfords socket set 😜 and it has taken me a little over 3 short days.
im well happy

PAVGR

iTrader: (2)

Congrats buddy for the swap although I was expecting to tell us if the 3GR ECU is a direct swap.
Jeff I pmed you about the 3GR ECU pin out !

Mattyc007

I do intend to try the ecu i just want to put a few miles on the car first.

Mattyc007

curiosity before i try it are the pin outs the same as the 4gr ecu?

liquidh

Hi, this is my first post. Thanks for all the very helpful comments.

My question is whether we could simply plug in the GS300 ecu to solve the “leaning out” problem with a transplant from 4GR to 3GR?

DulceSeek

Can anybody confirm leaning out problem after the swap?
I created thread on that and I had a response that it should be fine due to compression ratio difference of both engines. This solves air but I can imagine that it would fade out without enough fuel at some point. Has anybody experience that can anybody comment on that? Speaking about swap only no SC kit.