The Toyota Landcruiser Owners Club

[annanku]

Hi been looking at re mapping the ECU for my 2005 LC4 (120,000 mls) from a reputable company, but still slightly sceptical if I'm wasting my time or not & if its not a good thing to do in the long run. Hoping to reduce the fuel economy a bit & as a steady driver not too bothered about the increase in performance but it would be welcome. Just wandered if anyone's had any experience with this or any comments. Thanks In advance

[Google]

[Juddian]

The word used to be that Toyota ECUs couldn't be cracked, though i understand this to be no longer the case, still not sure i'd be letting anyone interfere.

Some people have fitted tuning boxes of varying types to these vehicles, even Toyota dealers themselves supplied the (Steinbauer i believe, probably the best available) units as a kit,  for a period you could buy new 120 and 3 litre Hilux with the units already fitted supposedly rated @200hp.
Plus there's always tuning boxes of some sort available to buy from the usual auction sites, most of which increase fuelling.
I'd be inclined to watch a few videos from fourby4Diesel on youtube and see what he thinks about overfuelling and the damage that can result, he's seen lots with cracked pistons due to overfuelling.

I'd be surprised if you noticed any improvement over what you could achieve by driving as economically as possible given the state of our roads and the traffic volumes encountered.

No Landcruiser/Prado with permanent 4WD is ever going to be an economical vehicle, but you can make the best of things by making sure the vehicle is running as well as possible, the brakes well serviced (most important as prone to seizing pistons) the tyres not too low in pressure and not too aggressive in tread.
The cost involved might be better spent getting the engine live readings read on techstream and see if the injectors themselves are in need of attention.

For what its worth, i bet most of us in general running around if it involves town and traffic see around 25mpg +/- 2mpg either way, you are doing well to see over 30mpg with an automatic 120 on a run and that's only by keeping it under 70mph, i got slightly better fuel figures from the automatic Hilux with the same engine, probably the result of the vehicle being slightly lighter and it was new plus being RWD only in road use.

[TONYCY11]

I agree with Juddian remapping the ecu or buying tuning boxes is mainly done for more power gains , and very rarely give better economy as both include increasing the fuel intake ,   and that greatly increases the chance of cracking one or more pistons due to more fuel use = higher combustion temps , as well as in the real world worse fuel consumption , much better fuel consumption is gained by a lighter right foot beingless hard on the brake peddle by anticipating the traffic ahead and making sure your tyres are not under inflated and making sure your car is in good state of tune including brakes and suspension .

[AlPrado]

[Beekeeper]

The plug in units are widely available and can easily be removed again.  I've not heard bad things about them and several of the vans at my work have them fitted by our workshop (not Toyota's though).
I wouldn't be fitting one to my LC though and here's my reasoning.  Presuming the LC is a diesel it is capable of just over 30 mpg on a run.  It's unlikely that ECU work would improve this by more than 10%, ie 3 mpg.  You would have to drive a lot of miles in a year for the exercise to be worth it.  I reckon 10% saving on 10,000 miles a year at current prices is around £260.  Maintenance, tyres and tyre pressures could save the same.  I wouldn't be disturbing a 17 year old engine for such a small gain.  If you drive around town or tow a lot then the figures are more favourable but the risk of engine damage greater as it's working harder.  If you do decide to go ahead I would be interested in the details and results.

[Tractionman]

I think that with 're mapping/plug in units whatever, the main goal with some is performance i.e. power over economy, which to some seems acceptable if they havent got their thinking heads on, rather than striking a happy medium.
Squeezing more power and introducing more heat can be a recipe for disaster, aside from the economy issue.
Without going over the top for power, there are other more acceptable ways of making your engine more efficient, cleaner and not wasteful of the power they already have by being sensible in your chosen methods, as proven by a well known member.

[Juddian]

We did have one car remapped, wifey's Citroen C2 VTS with the 110hp 1.6 Diesel.

The reason for remapping was that under about 1800rpm the engine was flat as a fart, then all of sudden it would pick its skirts up and go for all of about 1200rpm rev range, made it quite horrible to drive having to be in the right gear at all times, can't be doing with it, something shared with many turbocharged engines having less than 500cc per cylinder.
The result was a much more flexible car with power coming steadily on stream from tickover upwards, didn't do anything for economy and nor was it expected to and nor did the tuner make any such claims, it did make the car much more pleasant to drive normally, the extra 30bhp and unknown gains in torque made it a surprisingly rapid pocket rocket.

Thing is none of that reasoning applies to a 3 litre Toyota Diesel running well, even from 1000rpm or less you can hear the turbo spooling up with smooth power delivery right through, the only thing that's ever held any of my 3 litre Toyotas back is when the fuel filter need replacing, you can fell it pulling back at higher revs requiring more fuel when it needs changing, same as almost every turboDiesel i've driven in lorry world then.
My 70 series, the first LC i owned with the 3 litre turbo lump was manual transmission, you could drive that all day on just the whistle from the turbo, that would pull cleanly from 800rpm, almost Cummins like.
Put your foot down in a 120 and she'll take off at a surprising rate in standard tune, even from tickover having 750cc in every cylinder means a fair lump of torque even before the turbo has produced enough compressed air for the rising torque curve.

In practice with the 5 speed auto,  i find the engine seldom gets above 1800 rpm on my normal commutes whilst keeping up with all normal traffic, i'd not wish to alter the mapping in any way and risk spoiling this relaxed truck like progress.

What did you decide OP, have you read these posts at all?

[Markus1967]

Gents

Just to let you all know, I remap ECU'z and during lockdown came up with a design that can reduce your emissions upto two thirds, going to jump on the proverbial band wagon before 2030 also, this can reduce your Tax Classifications

[karl2000]

Wow, how do you get them to change your tax classification?  Whats involved in that?