Thread: The D2a Diesel with never changing fuel economy

No help with your problem but sounds just like my D2 only a bit different . No lift std tyres etc. Only ever got ~650 +-10 km per tank . Each mod/repair made would net ~750 km per tank for a full or two and then drop back to 650 . Best change I got was replacing the air pressure sensor by the air filter . Std ecu and mild chip in ecu same . New ecu with sport tune same . Just had ashcroft t/c fitted hopefully that may improve things.

Will follow thread and see if you find the problem .

Chris

For what it's worth there may have been a clue early on in this discussion.
I too have noticed that after a brief disconnect of the battery the car drives better and gets better economy. My personal opinion here is that my auto box must be logging an internal issue and the torque converter stops engaging, hence the engine runs at higher revs. I only truly notice this on the freeway as around town it only feels sluggish.

I think my auto is on the way out but can't decide what to do with it.

Only the transmission ECU is adaptable, so if the vehicle is changing, then its the gearbox adapting back to changes from the engine tune.

The Transmission ECU can ask different behaviours of the ECM eg reduced torque output.

I'd be investigating this...

Try resetting the transmission adaptations each tank for a few and see what you get...

Originally Posted by Yorkie

haha, snowwhite, he'll love that!

DiscoWhite, my bad.

Originally Posted by Yorkie

as to the economy that does seem odd, did the auto ever get rebuilt and could that be affecting the ecomony due to incorrect shift points?.
maybe install a sail, that might bring some gains.

As far as I know, the automatic transmission was never touched. I have no paperwork to indicate that it was (and he gave me a lot of paperwork with the vehicle). I have read his old posts on it and he seemed to think it was fine.

The tranmission fluid in it stays nice and clean. I have a temperature sensor in it connected to the MadMan EMS. The temperature is generally spot on perfect indicating that it doesn't have additional resistance.

I have an Ashcrofts heavy duty torque converter that I will install into the vehicle soon too.

Originally Posted by simonmelb

Any Nannocom reported errors?

I will check. Last I recall the only error was due to the missing solenoid in the air line to the turbo (this is removed and disabled for the VNT upgrade).
Do I need to drive the vehicle first before recorded reported errors? Or can I just go outside, start it, plug in the Nanocom Evolution and record the errors that arise?

Originally Posted by td5inside

As I already told you, Phill request us a super mega super extra mega powerful map...and that´s what we did eheh
He had some flat spots some other remaps and we managed to correct them!

The new map we made for you is less powerfull ...

Yeah, that is why I was hoping that the bad fuel economy was due to the 'super mega super extra mega powerful map'. Once I loaded the new map and achieved the exact same fuel economy, I figured the problem lies somewhere else in the vehicle and not with the ECU tune.

Originally Posted by td5inside

Get some fuelling readings with the nanocom and send them to me... I will try to see If anything strange pop up and help you out with this!

I have e-mailed you some some *.CSV files that the Nanocom Evolution has produced. I recorded these through the DISCOVERY II / TD5 / TD5 ENGINE / INPUTS FUELING function on the Nanocom interface. I hope these are some assistance.

Originally Posted by OffTrack

I'm wondering if it might be something like a fuel temp sensor, hence the recording of ECU inputs.

I have also put these online on MediaFire for download for anyone else interested in seeing them:
http://www.mediafire.com/?jvnbxeiql9392mk
http://www.mediafire.com/'d17w6an073zop3j
http://www.mediafire.com/?83m0md3p6s6g3dt
http://www.mediafire.com/?x1cc715ex0jd9d8

These files were recorded over the last two days. They are some fairly typical drives that I do daily in my Discovery 2 TD5.

Originally Posted by td5inside

Just pop-up in to my head while reading your other post....could'nt this be a problem with the speedo??? I remember that a costumer of us had a similar problem (he changed tyre size) and we had to make speed readings from a gps and a terratrip... the speedo error was enourmous!!!!

Originally Posted by td5inside

I´ve answerd you on the other post regarding this subject, but....could'nt this be a problem with the speedo??? I remember that a costumer of us had a similar problem (he changed tyre size) and we had to make speed readings from a gps and a terratrip... the speedo error was enourmous!!!!

What if, your speedo is reading 100km and In fact you are running 120 or 130 km?!!!

Highly unlikely. Whilst I do have larger tyres (32") - 18" wheels fitted with 255/70R18 - I have fitted a TrueSpeed spedometer adjustment unit. The speedometer on my dash is pretty much 99% spot on accurate. It is exactly the same reading as my Garmin Nuvi GPS and spot on when run along side my 2002 Ford AU Series 3 Falcon XR8 Pursuit 250 which has a standard geared and sized driveline. I believe that this same signal is the one used by all the electronics on the vehicle and therefore everything is getting the correct speed signal.

Originally Posted by Blknight.aus

if we were to blame the map, my opening guess would be the injection is retarded so your not getting everything you could out of it.

I hope not. Jose seems to know what he is doing, and he has been wonderful to deal with. If this is the case then hopefully the input readings I have provided him with would help to indicate or diagnose it.

Originally Posted by Blknight.aus

more realistically tho if everything seems to be performing normally Id start by looking at the exhaust, very similar symptoms occur if


you have excessive restriction in the exhaust
if the wastegate is opening to agressively or not closing off correctly.
the EGR butterfly is not opening all the way.

The exhaust has been de-restricted from factory. It is 2 1/2" factory pipe with all factory standard mufflers, resinators and cat converters removed. I have two high flow straight through hot dogs fitted - one in the front pipe (where a cat converter would be fitted) and one in the tailpipe. In the center is a Lukey high flow straight through muffler. In addition, Phil, removed the exhaust flexible joint as he discovered that these were a restriction in the exhaust system due to their small internal diameter - he replaced it with a true 2 1/2" one to eliminate the restriction.

The wastegate is part of the turbo correct? I have only recently replaced the standard turbo charger for a VNT. As the wastegate is part of the turbo charger, I have therefore replaced this with a brand new unit. I saw no difference in fuel economy when I changed the turbo charger from standard to VNT.

I do not know the EGR butterfly. But all of the exhaust recirculation equipment has been removed from the engine, so I am assuming this therefore is not a possible issue.

Originally Posted by Blknight.aus

if its an auto you might also be getting some flare on TC or in the clutch packs, ID start by following the auto diagnostics drive test after doing a stall test to see whats what in that department. It doesnt sound like an auto problem if its towing ok but thats likely to be the most expensive bit to fix if its the problem so lets eliminate that first.

Yes, the vehicle is automatic.
I will do some tests and diagnostics on the automatic then and advise of the results.
I assume the stall test is just to have left foot on the foot brake pedal and right foot on the accelerator to see how high the RPM flares up.
How do I do an auto diagnostics drive test?
Due to all the additional modifications making additional power, the current stall speed is very high. I have purchased an Ashcroft heavy duty torque converter to rectify this - I just haven't yet had a chance to instal it.

Originally Posted by Chris77

Only ever got ~650 +-10 km per tank .

I dream of fuel economy that good!

Originally Posted by eckolsim

For what it's worth there may have been a clue early on in this discussion.
I too have noticed that after a brief disconnect of the battery the car drives better and gets better economy. My personal opinion here is that my auto box must be logging an internal issue and the torque converter stops engaging, hence the engine runs at higher revs. I only truly notice this on the freeway as around town it only feels sluggish.

I think my auto is on the way out but can't decide what to do with it.

It is very rare for me to ever disconnect the battery. Most of the time when I work on the vehicle I leave it connected still.
But I will try it.

Originally Posted by Tombie

Only the transmission ECU is adaptable, so if the vehicle is changing, then its the gearbox adapting back to changes from the engine tune.

The Transmission ECU can ask different behaviours of the ECM eg reduced torque output.

I'd be investigating this...

Try resetting the transmission adaptations each tank for a few and see what you get...

Ok, I will try resetting the transmission adapters. I have just been looking through the Nanocom Evolution menu to see how to do this - DISCOVERY II / MOTRONIC / D2 AUTOGEARBOX / UTILITY seems to be the menu - I assume that I then press RESET ADAPTIVE VAL.



Thank you to all those that posted and commented in this thread, I appreciate the input, thoughts and ideas...

That is correct, will be interesting to see how it goes then for a few tanks...

(Dont forget to reset it each tank for a couple to see if anything changes)

Originally Posted by Tombie

That is correct, will be interesting to see how it goes then for a few tanks...

(Dont forget to reset it each tank for a couple to see if anything changes)

Cool, ta. So I only have to reset it for each tank, not every time I go for a drive?
A tank of fuel usually lasts me almost two weeks, so I'll fill up later today but it'll be a while before I know.

EDIT: just reset it, see how it goes.

Only each tank for this experiment....

Originally Posted by simonmelb

Any Nannocom reported errors?

I have just run all the tests I could find on my Nanocom Evolution to try to find any reported errors (these are found in DISCOVERY II / TD5 menu on the Nanocom Evolution interface). These were all recorded with the vehicle just idling in the driveway (it hasn't been driven in approximately 2 hours):


TD5 ENGINE / FAULTS:

I saved the following text file:

NANOCOM - TD5ENG.APP - TD5 ENGINE fault file

(2,8) AMBIENT PRESSURE CIRCUIT, (LOGGED LOW).
---
(4,3) COOLANT TEMPERATURE CIRCUIT, (LOGGED HIGH).
---
(20,5) EGR VALVE STUCK CLOSED, (LOGGED).
---
(2,1) ROAD SPEED MISSING, (LOGGED).
---

I will go an rerun this test though, as the only error that displayed on the Nanocom Evolution screen is the AMBIENT PRESSURE CIRCUIT error.
I am fairly certain the error (2,8) AMBIENT PRESSURE CIRCUIT, (LOGGED LOW). relates to the missing and disconnected solenoid that goes in the air line to the turbochargers wastegate.


SLABS / FAULTS:

Nil faults.


ACE / FAULTS:

The first time I ran it, I got the following which I saved as a text file:

NANOCOM - DISCOACE.APP - DISCOVERY ACE Fault file

Fault 03-04
PRESSURE CONTROL VALVE FAULT
---

I then cleared the faults and ran it again and go nil faults.


D2 AUTOGEARBOX / FAULTS:

No faults.

D2 AUTOGEARBOX / SETTINGS reads the following:




Should I write a VIN?


D2 AIRBAG / FAULTS:

Came up with two Errors:

ERROR:
ECU communications error...

ERROR:
Unable to start communications with the ECU

I intend to clear and run the TD5 ENGINE / FAULTS again shortly.

Originally Posted by Blknight.aus

ID start by following the auto diagnostics drive test after doing a stall test to see whats what in that department.

I did a stall test (left foot on the foot brake pedal, right foot on the accelerator). The vehicle reved up to 3,125 RPM approximately (the tachometer needle was between the 3,000 RPM and 3,250 RPM markings on the tachometer).

As I mentioned above, the Nanocom Evolution did not produce any faults for the automatic gearbox (DISCOVERY II / TD5 / D2 AUTOGEARBOX / FAULTS menu on the Nanocom Evolution interface).