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Motec 1KD Driveability tuning.

Practical Diesel Tuning

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Hi all,

I have been battling drivability tuning with my hilux for over a year now. I have been in contact with Motec for assistance and it helped quite allot but i can never get the truck to drive smoothly no matter what i try.

I have tuned the feed forward tables and P gain tables but i just cant seem to get it right. It surges quite a lot going from a standing stop through first and second shifts. (manual gearbox)

I have had a issue with the mass airflow calibration that i have now fixed but it still does it and it's driving me insane.

I'm guessing the injector linearisation tables are off quite a bit but i'm not sure the correct process to correct these.

It drives fine at cruise or 3rd gear and above where the engine rpm isn't changing as quickly.

I have had it on my friends dyno recently but the dyno puts too much load for low down tuning in steady state so it makes it hard to tune the real low end parts of the tables.



What injectors are in it? Standard or bigger?

Its running the standard injectors. I have done front mount intercooler and 3 inch exhaust i also made a equal length-ish exhaust manifold and a custom down pipe to the front of the turbo. And i removed the EGR system.

The guys at HPA had a similar issue on their Hilux that I was able to largely clean up for them by softening the 'Drivers wish table'. The drivers foot would porpoise on the pedal during shifts and cause a nasty feedback loop of lurching. Pulling some fuel out of the of lower throttle positions (50% and below) seemed to eliminate it.

Hope this is helpful,


Thanks for the reply Nick,

I have tried that approach also and it work a little bit but i found that if I take too much out it feels too un responsive. I also added about 30ms of voltage filter to the throttle pedal and that helped as well. I'm glad to know I'm not the only person having this issue.

I have put allot of thought into why it might be happening. I'm guessing the OEM will be using torque based tuning which will be limiting aggressive fuel mass changes down low in turn making the vehicle smoother to drive.

I have considered trying fuel mass limiting via gear but the ecu has a hard time estimating when it is in first gear (no gear detection on gearbox).

I also appear to have allot of lash in the driveline between the gearbox and the rear tires and i feel that this is contributing to the feedback loop as well.

All in all i have learnt to drive it softly enough that its manageable. Hopefully future firmware releases from Motec can help solve some of the issues people are having. Not that there are allot of us out there running this setup anyway.

OK i will try to keep it simple.

First things is you need to accept your Motec is a very basic diesel ECU with only a single layer torque control strategy that becomes very jerky very easy. Also the fact that a MAF is used is nothing close to a normal diesel aftermarket ECU standard where MAP is used so this really annoying MAF senor can be deleted.

Using MAF will soften things up a bit with torque control as its slower in response freeing up fuel more gentle if you set the smoke limit on lower fuel amount and start working your boost request map so a lower accelerator pledge position give low boost/lower fuel amount. Next things your able to do is lower the torque request numbers on lower accelerator pledge position so it becomes more gentle on low and mid power request from the driver.

Result is very lazy on low decelerator peddle position and from about 70% decelerator peddle position things will start moving on torque numbers very rapid.

Debounce or putting a voltage filer on the accelerator pledge response will help a bit but it will makes you torque response lazy and really not needed as we run these Toyota engine over 800Nm on Rally cars.

In all some of the ECU we program go to 5 layers on torque control strategy to get that instant stabile power response from your diesel engine. Also the ones that work on OEM diesel systems know that often have to work very hard to understand torque control strategy so in all not a easy job for those that do not have the background on diesel engines as it’s nothing close to petrol engine.

All I can say even our most basic aftermarket diesel ECU is able to run 1000Nm per 1000Kg with good low end response and drivability getting that OE feel you from a modern diesel.

So looks like you done most things already and you may want to consider moving to a other ECU platform to improve things.

Thanks for the reply Rudd,

Unfortunately going for another aftermarket ecu is kind of out of the question for me. Its either stock or what I have. The motec system cost $6000 NZD and i would like to use it if i can. Im beginning to see the limitations with it however for driveability tuning however making peak power is easy as im sure you know. I have got it running fairly well now so will just keep chipping away at it. Perhaps they will release firmware in the future that address some of these issues.



Well let this be a warning to those thinking of using a aftermarket diesel ECU system.

Some are overpriced not delivering even the most basic functions and second to this most can be done by OBD tuning and so on.

I worked on diesel engine all my professional live building R&D diesel ECU in house and only using ECU manufactures that we are able to develop with us and we know there products are working and yes these ECU manufactures are not in your face selling you stuff that dos partly work and are widely advertised by others. You have to look for them and they are decent priced and can be used for most car engines and have all the options in there even OE traction control by CAN is in there same a nitro and water injection control if you into funny stuff.

Can you recommend some of these brands then?

Yes no problem.

We start using these systems and work close together with them. https://controls.is/shop/ecu

The software is not that good looking but dos the job well and yes you need to know diesel ECU systems as things are not in the manual in detail so yes a bit more back to basic there.

Done some explanation on youtube as well. Note that in the gauge menu @ the beginning you see a cylinder effort deviation indication and yes this ECU is able to balance out fuel over the cylinders and trim them out. Great function for engine that run on diesel fumes like some Mercedes engines easy making 1200Nm out of 3L engines on big injectors. Also no in real live this map run a 15.6L V8 and the numbers in the mapping must be done x10 so 50 is 500mm stoke or 0,5cc stroke [url=https://www.youtube.com/watch?v=rQzem96bbB0]https://www.youtube.com/watch?v=rQzem96bbB0

Thats a fantastic looking system Rudd,

The interface is not really an issue as long as it does the job. What is the logging software like? Does it do realtime graphing?

The price is good as well. It really highlights the features where Motec is lacking in the fuel map department.

Im going to stick with my solution for the moment but if there is no improvement then i would be interested in trying this system out in the future.


Internal logging 8 GB On board data logging memory Capable of recording data at up to 1000Hz on selected channels or every channel simultaneously at up to 500Hz. Real time clock for log time stamps.

And there is real time logging in data and graphic as well using F1/2/3 functions in the software and parameters can be selected. Software has data analysis in it as well. Please read the manual about it and its free of charge.

Also a thing I want to point out. Aftermarket diesel ECU manufactures are often followers not developers and this can create workarounds often resulting in excessive feed forward tables for example able to get some sweet spot not really understanding what running a diesel engine is all about and even making a small chance to your set-up will be called a compromise as you will jump out of that sweet spot. Monkey see monkey do will not do the job as real understanding is needed and yes most doors on getting good information from the diesel industries are closed to the outside world.

It’s also the way of thinking with diesel engines. How about this one. I upgraded my engine by downgrading my fuel system and yes got more engine power but fuel economy not so great.

Can we have both? Yes you can. How? Well that’s not so easy as your now probably end up on the other side of the diesel industry OE related where stability and quality are NR1.

Professional diesel motor sport is improving on all things more engine power less fuel consumtion less fuel need lower vehicle weight wins races being on top of the game developing. Good thing is diesel combustion is now becoming so fast that’s some things start looking like a petrol engine. For example the decay on engine power on over fuelling your engine goes a lot faster even the point smoke turn grey not even black and a 14.5AFR can be run on a hot engine. No visible smoke. So stay tuned al do I think most of the good stuff will stay on truck and industrial engines as all steel internals are needed to run these hi combustion temperatures.

Just went through the software its pretty easy to understand. Im going to start pressing motec for more updates for their firmware. They havent released anything for 2 years. It makes me wonder if they have stopped developing the diesel package.

Some pointers on aftermarket diesel ECU why it’s not massive on sales so is there a motivation to upgrade?

Most can be done by OBD tuning so not a lot of need for a aftermarket diesel ECU. We only do aftermarket for motor sport and it’s illegal for road use let alone it meets emission standards.

Toyota plug and play is done with one of my Asian customers maybe with the thing in mind making good sales as this is one of the biggest pickup marked. Did this happen? To many other options to get the same result. Piggy bags.

Monkey see monkey do or copy paste things that you did not create. Will intellectual property be respected. Often not! Sales and marketing dominate on some parts of the marked.

For those asking me to help out on OE ECU stuff. I’m not involved in any OE ECU changing stuff or explaining there workings in detail. NDA goes with R&D and visa versa. If you need some information go look good on the internet maybe you will find a forum with your question on it. Torque control strategies and there working are a no go for me on the info part but all a bout combustion related stuff no problem.

Yeah i get the lack of standalone support in the Diesel world. And finding people who know about it and are willing to teach is even harder.

Here in NZ we can get away with running aftermarket ECU's and not get into trouble with emissions regulations.

If i find in the future that Motec will not support there product i would consider the Baldur DID1 system. Is this something that you would be able to provide support on?

I'm curious about Baldur's CAN implementation. I'm using a 5in AEM dash to display data so I can keep an eye on things without having the laptop in the truck.

However my setup is for the street and some off-roading so it need to be able to work with the factory systems as well. I see in the documentation that the ecu is working on the older 1kd engines. Mine is a 2012 euro4 variant.

If you bay the ECU from us yes you get support even online we can take over as longs as you have Wifi.

We are able to set-up any can in or out on these ECU and it has 2 can lines.

We done your engine as well. Difference is the fuelpump control on the older model.

Ah right,

Well lets see what the future holds. Like i said if i have no luck with my current setup i will be in touch.

This is our latest creation that goes to Daker Rally middle east end of this month.

The ECU on this engine is insane on what it can handle. You can call it next level and way over the top to drive a all day ride but not so hard to scale things down a bit on functions that actually work on most engines and if not we come up with a solution for it.


Damn that thing looks insane. Nice work on the build.

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