TD6 economy

[donrover0]

I had been watching my economy slowly degrade over last year. I work 200km west Toowoomba and fuel consumption been 10.6L/100km for months now.
Yes, new air filter , etc, etc. and now 240,000km
Other day had a few hours to spare so FINALLY bolted in EGR bypass/block and a tuning box. Both these been sitting in back of car for 6 months!
Last trip out west, pleasantly surprised and hard to believe, average now 8.3L/100km.
On 100km stretch, flat going, it was sitting on 7.9! at constant 100kph. the average rise due to town and hilly highway driving.
No, I can't remember the name of the tuning box, but it plugs into sensor at end of common rail. It can be adjusted up/more power or back/economy. it cam preset about at 33%. UK supplier.
Next week I will be on trip to Snowies so will be able to give it a real test! About a 3000km round trip

These by dash display, which also underreads speed by abt 3%; checked with an external/ not RR GPS.
Power? at current setting does seem more responsive

[Homestar]

Nice going. Ours was sitting on 11.8 (overall average) and getting down to 10.5 on the highway. It's back on the road after a new turbo, head was off - all crud from EGR cleaned from the valves and intake manifold and it has settles down to 10.8 overall and drops to 9.7 on the highway, so I'm pretty happy too.:)

[donrover0]

Module is "C.R. Tech" from Blue spark, UK

When I bought this car a year or so ago, drove it back from Melbourne and it , then, averaged 9.5 for the whole trip. Since added bullbar, side steps, 3 roof rails so maybe that did it.
I did have suspicion about the EGR valve, but it was pretty clean.

Snowwy trip, I'll do tank to tank consumption to compare with the dash readout.

[Dougal]

Tuning boxes screw with the accuracy of the dash fuel readout. You'll have to run a few tanks to see what it really does.

[disco gazza]

Hi Donrover,

Which EGR bypass did you buy.

Thanks

cheers

[donrover0]

Now that I've done another run, I see that dash readout is screwed! Up and down!
at one stage it showed 9.6 at 110kph, then 10 at 100kph; I then towed a 3 tonne fertiliser spreader for 250km and it showed 15.5L/100km.
I think that one was close/could be right?

The EGR bypass was just the cheapest I could find on Ebay about 8 months ago; I think it was GBP25 + postage GBP12. I did have to file off the pipe that extended a little through the flange; after that it fitted straight on/OK.

[harlie]

Dougal is right. The dash read out for consumption is derived from calculations based on the throttle position. A plug in box just pours more fuel in without the ECU knowing about it.
Plug in boxes also throw the timing out slightly – they can’t compare to a remap.

The bypass would be giving the improvement.

[donrover0]

I agree that a remap is the ideal and most accurate form of injection for either economy and or more power.
I beg to differ re fuel consumption readouts; I believe it is a result of signals direct from the injectors to the computer in the instrument pack where it is calculated.
Throttle position? the only "throttle" in this system is the foot throttle and when on cruise this is in "zero throttle" position.
This plug-in box is supposed to learn the current driving situation , then adjust accordingly and is always communicating with the ECM and "suggesting" a slightly different/variable map. It has 2 selectable programs.
I have yet to screw it fully back to " economy" setting, but will soon.

Yes, of course EGR bypass contributes to economy.

[Dougal]

I agree that a remap is the ideal and most accurate form of injection for either economy and or more power.
I beg to differ re fuel consumption readouts; I believe it is a result of signals direct from the injectors to the computer in the instrument pack where it is calculated.

The computer calculates how much fuel the injectors will spray at the current rail pressure and uses this to calculate fuel used.

But these "tuning boxes" increase rail pressure while tricking the ECU into believing it hasn't changed. The result is more fuel sprayed than the ECU knows about.
The end result is a dash fuel economy readout that is wildly over-optimistic.


Throttle position? the only "throttle" in this system is the foot throttle and when on cruise this is in "zero throttle" position.

When on cruise the ECU receives it's throttle command from the cruise control.


This plug-in box is supposed to learn the current driving situation , then adjust accordingly and is always communicating with the ECM and "suggesting" a slightly different/variable map. It has 2 selectable programs.
I have yet to screw it fully back to " economy" setting, but will soon.

How many plugs does this "tuning box" have?

[harlie]

...

I believe it is a result of signals direct from the injectors to the computer in the instrument pack where it is calculated.

.....

I agree with dougal. It is a calculated "measurement"

There is no signal back from the injector to any ECU - the injector does not transmit any signal - the injector harness is completely anologue. The engine ECU monitors the injector for closed circuit (or not) - the ECU has no idea how much fuel the injector has put in. This is why injector issues often don't throw a fault, you can have a dead piezo/solonoid allowing zero fuel in and the ECU would not know a thing - it detects something connected on the harness but has no idea it isn't opening. The injector has no mechanism of measuring volume, has no knowledge of pressure, it just opens and closes on command.

There is a "throttle position" variable that the engine ECU uses to fuel. As Dougal mentions that either comes from the sensor under the right pedal or from the ECU when on cruise control.

Most new petrol engines have a "choke", doesn't mean there is a flap in the air intake, it is just a ECU parameter constant that when invoked, gives higher fuel mix when cold.



This plug-in box is supposed to learn the current driving situation , then adjust accordingly and is always communicating with the ECM and "suggesting" a slightly different/variable map. It has 2 selectable programs.
I have yet to screw it fully back to " economy" setting, but will soon.

...

Suggesting? Hey? How does it do this. The TD6 ECU (I bet any car) does not accept map changes from other ECUs – another ECU would have to be accepted into the group, and the functionality would have to be written in the original car. AND The fuel map files cannot be updated, only overwritten – it is deleted and a new one copied in. The engine would stop while this process is happening because for a period there would be no fuel parameters at all - so this is one super magic box.

No matter what functionality is programmed into a box, if the car ECUs do not have the functionality to accept "suggestions" they ain’t going to happen.

The majority of these boxes alter the analogue signals - either between the engine ECU & injectors (hold them open longer) and/or ECU & sensor/s (modify the signal to fool the ecu into thinking boost pressure needs to be increased for example) - most of them aren’t even on a digital BUS to be able to suggest anything. The ECU has no knowledge they are there, if it did, it would fault it's arse off.

Direct from BlueSpark web site - “This enables the tuning box to modify the signals from the ECU in real time” – It is not communicating with anything, it is just intercepting, adjusting and retransmitting the analogue signal on the harness – and it is not truly ”realtime”, it can’t be, there is processing time, so any signal is delayed, only by a millisecond or 3,4,5, but it is delayed – that is the big difference between a box and remap that their site seems not to mention.

Do you really think for 149quid someone can develop a custom ECU that integrates digitally on the proprietary BUS? It would be completely different for every vehicle – just ask Black Box solutions how different the LR range is – let along other manufacturers. There is a reason remaps are more expensive – because even the “off the shelf” files are still custom writen for each model on a dyno. These boxes are just a fancy voltage regulator, with a different plug - they are far from clever.

[donrover0]

I hear what you're saying.

Tomorrow driving Toowoomba to Threadbo; tank full to brim; trip meter on zero.
Consumption 2 reset.
So will compare!
If different, I wonder if the consumption correction proceedure/ change the correction factor, will work in this situation?

[bluegreygreen Rangie]

Having my battery disconnected today i lost my fuel stats but i was on 9.9L/100k for about the last 40 thousand ks which consists of some longer than usual idling.. some towing .. around town and some big interstate trips... i drive pretty easy only sit on 100ks etc but always have half tonne of tools in the back

A bad fuel injector which i am about to replace would have made these figures worse too

Egr deleted, K&N filter, Oh yeah nearly 400 thousand k's on the clock :)

Some one mentioned about newer petrol cars ecu's providing a richer mixture as a "choke" when the engine is cold... i believe the TD6 does this too as my car pulls very hard all on its own without any extra throttle input but only when it is cold, If i reset a fuel consumption meter it reads very high during this time



Dave

[harlie]

...

i drive pretty easy only sit on 100ks etc

....


And that is what affects economy the most.

she's done nearly 400ks, that's impressive




... i believe the TD6 does this too as my car pulls very hard all on its own without any extra throttle input but only when it is cold, If i reset a fuel consumption meter it reads very high during this time


Dave

You're right Dave. The engine adjusts fueling for temps below 80- 82

[bluegreygreen Rangie]

And that is what affects economy the most.

she's done nearly 400ks, that's impressive



You're right Dave. The engine adjusts fueling for temps below 80- 82


Yes its all in the foot,

After my next interstate run i should be right on the 400 thousand k mark.. the engine runs sweet except for one injector playing up atm but should have that replaced in a weeks time, Far as i know has never had the head off... i doubt turbo is original, when i get time ill compression test it and pull the head for a look inside and simply to replace the head gasket, I also want to check the oil pressure but have to find where to tap into a sensor etc

Would appear to be a very solid engine.. i think the head will be the weak link with high ks but i could be wrong

In putting well over 200 thousand ks between two TD6 Rangies i have not had many problems, two fuel pumps... one injector it would seem and a steering angle sensor.. oh and a broken ride height sensor if that counts


I really should not have said all that... im sure my gearbox will now explode next week... :twisted:;)





Dave

[Dougal]

How do your measured fill-ups compare to the dash readout?

[donrover0]

Back from run to snow last week.
The highway sections, 1300km each showed 9.3l/100km on MFD; actual 9.8 by tank to tank, with average speed 95.6km
All round trip, 3000km with few days crawling up and down and around in snow showed 9.8 on MFD and 10.5 actual.
Appears that this can(easily????) be recalibrated, according to owners manual/rave.
The MFD speed readout is 3kph slow at 100; as tested by gps, but speedo gauge spot-on at all speeds up to 100 kph.
Obviously the plug-in module not making any difference to fuel consumption, but engine definitely more "responsive"/power when required, especially when heavy towing.

I only paid A$110 for this (as quoted 420Nm) module, on clearance sale, so it can stay for a while; priced a 480 Nm remap at $850
Engine at 245,000km; uses between 1/4 and 1/2 litre between 10,000km oil changes.

[donrover0]

Oh, and engine started within 2 seconds in -6 degrees without glowplugs every day there; car covered in snow!
Glow plug relay faulty; since been replaced.

[harlie]

...
; priced a 480 Nm remap at $850
....


Don, you can get a Bluefin remap (505nm) for about $600 when they run their specials. They guarantee to improve fuel consumption. I found it getting better mileage on the highway, but worse around town.

Also wind makes a big difference. We traveled 200km into 20-25kn wind, back opposite direction that afternoon. Same load, road and temp - full 1L/100 difference between head and tail wind.

How heavy were you?

[donrover0]

Hi Harlie,
I've noticed the difference wind makes on my weekly 200km runs out to work; yes, at least 1l/100km difference!
On trip to snow; 3 people and full luggage.
I still believe that adding the SS/rubber bullbar, side steps and 3 roof bars have caused a minor increase in consumption to when I first bought the car.
I've now screwed this box to full economy side so will see if any difference. It still seems to perform better than prior!

[bluegreygreen Rangie]

How do your measured fill-ups compare to the dash readout?

From when i have checked the dash read out is telling me i am getting better consumption than i am by up to 1 liter per 100ks

Mind you this is if the bowsers are accurate and the level which it is re filled to etc,

And i also have larger than standard rolling circumference tires fitted (Attturo 275/55/R20), which would counter the computer reading better than it should

So what i really need to do is figure out exactly what i am using and calibrate the computer if it needs to be done i guess



Dave

[Dougal]

From when i have checked the dash read out is telling me i am getting better consumption than i am by up to 1 liter per 100ks

Mind you this is if the bowsers are accurate and the level which it is re filled to etc,

And i also have larger than standard rolling circumference tires fitted (Attturo 275/55/R20), which would counter the computer reading better than it should

So what i really need to do is figure out exactly what i am using and calibrate the computer if it needs to be done i guess



Dave

I calibrated the readout in my one car that has it (not a LR product) by plugging in a scangauge and using that to keep track of whole tank litres and km. You can adjust the scangauge up and down to the best fit (individual tanks still error +/- a few percent). Once you're happy with the scangauge reading, you can tweak the dash readout to match without having to do full tanks to test it.

My car was VAG so VCDS was the laptop plugin to let me calibrate this. I could wind it up or down by 15% either way. I don't know how the landrover interface works, but it's also bosch so it won't be too far different.

[33chinacars]

Would have to say mine was pretty good the last time I tested it over 1500 kms. Computer read 9.8 l/100 . Actual 9.65 l/100. So I'm not complaining :)