Bad diesel fuel consumption!

[12344321]

Hi I have a 52 reg 75 2.0 diesel with 103000 on the clock. I have a synergy box fitted and the air intake mod done and I am using the box on setting 2 and on economy mode and the mafam switched off.

If I swich the mafam section on does this help with the fuel problem? And does the synergy take out the need to buy a replacement maf sensor?

I filled up the other day £61 to the brim and now have only returned 400 miles.

I have had a mixture of roads motorways and bits and bobs along the way and dont drive hard. If anyone knows why I am getting such a low amount of miles out of my fuel can you help. Also does anyone know if I can just switch something on the roverron box to help?

Many thanks British and Proud Rover Peter

[GERFIX]

Hi I have a 52 reg 75 2.0 diesel with 103000 on the clock. I have a synergy box fitted and the air intake mod done and I am using the box on setting 2 and on economy mode and the mafam switched off.

If I swich the mafam section on does this help with the fuel problem? And does the synergy take out the need to buy a replacement maf sensor?

I filled up the other day £61 to the brim and now have only returned 400 miles.

I have had a mixture of roads motorways and bits and bobs along the way and dont drive hard. If anyone knows why I am getting such a low amount of miles out of my fuel can you help. Also does anyone know if I can just switch something on the roverron box to help?

Many thanks British and Proud Rover Peter
I worked that out to ROUGHLY 32-33mpg. Is your's an auto? If so, then depending on what percentage of M/way you have done then that doesn't sound too bad. I'm getting that mileage with my manual and that's 50/50 bypass and town. Then again, if you're mostly motorway then I'm sure it's not that goodhttp://www.the75andztclub.co.uk/forum/images/icons/icon9.gif!
Someone else will hopefully be able to point you in the right direction regarding the Ronbox.

[Raistlin]

32 mpg is what I get on a regular basis with VeeKay which has the X-Power 131 upgrade and Synergy.

That includes regular driving to work which is a distance of 8 miles door to door.

Being an auto, I'm happy with that, having asked the same question as you recently.

Longer journeys see the consumption reduce to 40+ mpg.

[JohnDotCom]

32 mpg is what I get on a regular basis with VeeKay which has the X-Power 131 upgrade and Synergy.

That includes regular driving to work which is a distance of 8 miles door to door.

Being an auto, I'm happy with that, having asked the same question as you recently.

Longer journeys see the consumption reduce to 40+ mpg.

I think Paul Means Increases to.....:D

[Raistlin]

I think Paul Means Increases to.....:D

No he doesn't - If MPG increases then consumption reduces ;)

[baxlin]

I have pre-facelift car with Tu3B, mafam, air intake mod, and EGR Bypass, and noticed increased consumption (or reduced mpg, whichever..........:D) of late.

Spoke to Ron who agreed a new Pierburgh Maf could solve it. At £57 ish, it was worth it just to try, and it has made a difference, certainly to the low-down performance, and although I've not done a full tank yet to check properly, I'm expecting that less need for a heavy right foot will improve the mpg.

If it doesn't, it's still better to drive, so a result either way.

Worth talking to Ron, maybe???

malcolm

[Jules]

Yes I believe an "out of spec" MAF overfuels the engine.
Our tourer Auto is returning 37 MPG purely town driving at MO.
On driving her home from Bristol 46 MPG was achieved.


John are you loosing yer marbles?:o

[GERFIX]

No he doesn't - If MPG increases then consumption reduces ;)
Agreedhttp://www.the75andztclub.co.uk/forum/images/icons/icon10.gif.

[JohnFol]

malcolm (and other MAFAM owners)

The instructions for the MAFAM says to set the dial to whatever o'clock. Where is 12 o'clock?

[paulmariner]

Hi I have a 52 reg 75 2.0 diesel with 103000 on the clock. I have a synergy box fitted and the air intake mod done and I am using the box on setting 2 and on economy mode and the mafam switched off.

If I swich the mafam section on does this help with the fuel problem? And does the synergy take out the need to buy a replacement maf sensor?

I filled up the other day £61 to the brim and now have only returned 400 miles.

I have had a mixture of roads motorways and bits and bobs along the way and dont drive hard. If anyone knows why I am getting such a low amount of miles out of my fuel can you help. Also does anyone know if I can just switch something on the roverron box to help?

Many thanks British and Proud Rover Peter



Mines an 02 CDT auto with 145k miles & it averages out at around 45mpg for all roads/conditions (although approx 60-70% is dual/Mway)
If I was getting less I'd get it checked out.

[baxlin]

malcolm (and other MAFAM owners)

The instructions for the MAFAM says to set the dial to whatever o'clock. Where is 12 o'clock?


IIRC, the minimum setting will equate to 8 or nine oclock, and the max setting is 3 or 4 oclock. So 12 o'clock will be midway (or midday??:D:D) between max and min.

But pm Ron if you're not sure.

[mash]

Mash here, i have the same problem, i wish i was getting half the MPG some of these others are getting.

[JohnDotCom]

No he doesn't - If MPG increases then consumption reduces ;)


I'll give you that one Paul,
a matter of translation from English to Welsh I'll blame it on! :D:D

[Roverron]

If you are using a Bosch maf and mpg starts to drop with or without a Synergy, then a Pierburgh maf should help.

My X-type (SYnergy on 6/7)averages 35mpg this weather and 2-4mile each-way journeys on slow roads. My 75 would probably do about the same.

Both improve to mid 40s on longer runs. I've never had 50mpg on a brim to brim fill up, but I never got that with my 45's either due to the way/speed I drive.

Some Mondeo & X-type owners also complain about poor mpg and I'm sure the common denominator is the maf sensor. Sadly Pierburgh don't do one that will fit and I'm loathe to recommend the clone mafs after my X-part experience. (I've now had all 13 I bought in June returned for refund)

As you'd expect, you need a bank loan to buy the oem ones.

Ron

[12344321]

Thanks guys! I will ask ron about the box. Does anyone know how to contact him or anyone have a email address for him?

The car is a manual by the way and thought 400 miles from 60 quid or a full tank aint that good. But if the synergy box has a maf swich on it does that mean I dont have to ever buy a new maf sensor? Dont get that part!

But I am glad that there is this site and you proud owners to ask thanks. Peter 12344321

[Roverron]

Thanks guys! I will ask ron about the box. Does anyone know how to contact him or anyone have a email address for him?

The car is a manual by the way and thought 400 miles from 60 quid or a full tank aint that good. But if the synergy box has a maf swich on it does that mean I dont have to ever buy a new maf sensor? Dont get that part!

But I am glad that there is this site and you proud owners to ask thanks. Peter 12344321

Just click on that big banner at the bottom of this reply or send me PM.

If you fit the Pierburgh maf, it should last a lot longer than the X-Part or Bosch ones but I can't say that you'll 'never' have to buy another.
At least the Synergy 2 enables you to compensate for any deterioration and therby extend its life. Plus, its only £53 to replace compared to £86 for an X-part one or £200+ for a Bosch one.

Ron

[Raistlin]

I'll give you that one Paul,
a matter of translation from English to Welsh I'll blame it on! :D:D

Theres loveleeeeee. ;)

[sylvester]

I have a 75 CDTi 2.0 Diesel Tourer. It regularly does 500 miles or more to a tankful (55 litres) and still has its OE electronic wizardry. So you are at least 20% down on your mpg and at 108.9 per litre.....

[Raistlin]

I have a 75 CDTi 2.0 Diesel Tourer. It regularly does 500 miles or more to a tankful (55 litres) and still has its OE electronic wizardry. So you are at least 20% down on your mpg and at 108.9 per litre.....

But in what sort of driving conditions though and is yours an auto?

[JohnDotCom]

Mine Is Paul!! :D and as Most know, I do 40,000 miles a year in it.

[Raistlin]

Mine Is Paul!! :D and as Most know, I do 40,000 miles a year in it.

Which sort of proves my point John.

Considering my relatively short routine journeys I'm not too concerned about anything being wrong with VeeKay - especially as Keith gave her a clean bill of health just before Christmas with his magic T4

[JohnDotCom]

The T4 does Inspire Confidence when you see No Fault Codes etc.

[Raistlin]

The T4 does Inspire Confidence when you see No Fault Codes etc.

It was all the engine parameters, injector values, MAF values as well John.

Made me feel even MORE proud of VeeKay, I can tell you :D

[12344321]

Thanks I have ordered a new maf from ron and it is on its way many thanks. Pete

[Keith]

Thanks I have ordered a new maf from ron and it is on its way many thanks. Pete

No offence but why?

If you don't know if your existing Maf is faulty or not then why mess about changing it?
A quick check at any X part dealer with a T4 can show you instantly if it is faulty.

[podge]

I do 500 miles per 7 day week(shifts), 80% on M3, try to keep to 70,try not to go above 3000 through gears(2500 feels happy), some stop start traffic and have been averaging 47 to 51, best was this week 53, new air cleaner and Millers in the tank.I check by old fashioned brimming,one thing I have noticed is that the engine seems to run smoother especially at tickover when not on supermarket fuel. I would certainly try a T4 test if in any doubts before spending money on changing anything.Best of luck....from another newbie.

[12344321]

I am changing the maf because I am sure it is overfueling the engine at the mo. I have changed everything else and all is up to date on the service side of things. I just think that it will help.... Anyway I know its done then and a few people think that it will work for the mpg to improve. I will keep you posted thanks Peter 12344321

[pondweed]

read the thread I've just posted on "37 vs 44mpg" and try that before you get the new MAF! Mine felt like it was overfuelling when I got it, but I know it had just HAD a new Rover £180 MAF....

[Roverron]

No offence but why?

If you don't know if your existing Maf is faulty or not then why mess about changing it?
A quick check at any X part dealer with a T4 can show you instantly if it is faulty.

The T4 test is not 100% conclusive in my opinion. Its a static test and cannot measure the maf signal when the turbo is producing significant boost ie the car is being driven.

If mafs always went out of spec in a predictable manner then fine, the readings that indicated a faulty maf would be valid, but they don't.

The only sure way is to substitute the maf. I have no faith in the X-part mafs, having had all 13 I purchased in June now returned. So, whilst some people may think I promote the Pierburgh maf and mafam or Synergy 2 just to make a sale, I remain satisfied that they are the best & most cost effective solution.

Finally, and sadly, just because a service centre has a T4 by no means does guarantee a correct diagnosis. Every week owners conact me after having been charge anything from a few hundred to a £1500 or more by dealer trying & failing to cure performance problems caused simply by maf issues. In many cases they are fitting 'clone' mafs which work little better than the out of spec existing one.

If only it was as cut and dried as you imply, Keith!

Ron

[desperado]

hi i have a 75 connoisseur se cdti 131 with a synergy box fitted. i found it more economic running full power not on economy,i have the dashboard switch fitted so can change it easy, haven't reset computer since june last year and averaging 48.7 on 6000 miles of mixed driving more motorway than town but still 30% town use. i've run it on normal diesel and biodiesel with no difference between the two. dan

[Jules]

hi i have a 75 connoisseur se cdti 131 with a synergy box fitted. i found it more economic running full power not on economy,i have the dashboard switch fitted so can change it easy, haven't reset computer since june last year and averaging 48.7 on 6000 miles of mixed driving more motorway than town but still 30% town use. i've run it on normal diesel and biodiesel with no difference between the two. dan

Are you aware that with tuning boxes fitted, your MPG computer will be 10% optimistic?
Only sure way is to do Fill to fill tank calculations.;)

[Roverron]

Are you aware that with tuning boxes fitted, your MPG computer will be 10% optimistic?
Only sure way is to do Fill to fill tank calculations.;)

Upto 10% optimistic! Depends on the setting.

Still, 44 mpg isn't too bad!

Ron

[apywell]

This topic gets talked about all the time. There is such a lot to take into account. For example, vehicle weight, tyre pressure, service, air conditioning/climate control, type of driving, engine temp, auto/manual, up/down hill, wind resistance, speed, fuel brand, etc, etc.

I have said before that using the computer I usually get a different MPG outbound than inbound using the same speed and road.

[sylvester]

But in what sort of driving conditions though and is yours an auto?
Mines a manual - mixed driving - we are in the South East. Continuous high speed (80) on european motorways where its possible to go from full to empty without slowing or stopping except for tolls or a pee the car can do nearer 600 miles on 55 litres

[Jules]

Upto 10% optimistic! Depends on the setting.

Still, 44 mpg isn't too bad!

Ron

Just sent a Chap called Ian in your direction Ron.
Sounds like he needs a new MAF & MAFAM;)

[JohnFol]

I tried to do the brim to brim method the other night. I had diesel on the garage floor the next day, so I think I might have found a possible reason for bad consumption . .

[desperado]

Are you aware that with tuning boxes fitted, your MPG computer will be 10% optimistic?
Only sure way is to do Fill to fill tank calculations.;)

hi . thanks didn't know that . p.s the v8 a stunner you've got for sale

[JohnFol]

I took the back seat out as its easier than jacking the car and removing wheel arch liners. The filter looks bone dry and is opposite the side where I could heel diesel on the underside of the tank.

I took the cover off the fuel pump and could see some dampness. I changed the pump about 1 year ago and used a new seal, so I am hoping that, as the large ring could easily be moved it just worked loose. It's now been dried and re-tightened so fingers crossed.


Just as a side issue, does the car calculate mpg by the level in the tank, or by some flow sensor?

[Jules]

Think it measures the high pressure fuel pulse width to the injectors.

A recommendation whenever the large rubber ring and collars are disturbed is to fill nearly to the brim with fuel and get the car inclined to the side to make sure no leaks before the under seat hatches are replaced.

[Roverron]

Just as a side issue, does the car calculate mpg by the level in the tank, or by some flow sensor?

As Jules says, its injector opening time plus rpm.

The Synergy/Tu3 reduces the pulse width because with the pressure being higher, a shorter injection period is needed to admit enough fuel to produce a given amount of torque. Hence the ecu calculates the mpg to be higher than it is.

The mpg reading should be most accurate at a steady speed of about 40-50 and will over read a bit more as speed increases. You should be able to deduce by how much if you know what it used to read at say, a steady 70.

Ron