How to improve 4.6 economy

[Robsrod 58]

Hi all,

Just returned from a whistle stop tour of Cameron Corner, White cliffs etc.

Fully laden with 2 full gerry cans, 2 x spare tire and Oz tent on roof and all gear in back including full 60ltr fridge food etc.. I weighed in at just over 3 ton. Bearing in mind I was running gas most of the way and only switching to petrol after Willcania, I returned an average of 17.2L/100 over more than 1000km of varying dirt road.

My question is, I really want to keep my P38 as it is probably the most comfortable 4wd I've owned and 'yes' reliable, what can be done if I had a budget of approx $7000 to improve this engines economy to a point which would be comparable modern petrol 4x4's without trying to transplant the engine with something else.

Rob

[benji]

Bosch gen3 injectors seem to make a difference, people were talking about figures as low as 11 with them.

Bare in mind though, unless your injectors are new or very clean and fuel pressure good the dash readout won't be very accurate.

Running on lpg will stuff around with that figure too as you may need more throttle on lpg.

Id say though, if you were getting 17 on petrol on the hwy there's something not quite right.

How'd the trip go? Would be nice and green through the Darling I imagine.

[Robsrod 58]

Benji,

Absolutely stunning, green everywhere not like when I was around there 10 years ago, the view from the 'Jump ups' was awesome, and how stupid are Emus!!, thank god Hoovers' got good brakes.

I think the trip computer is close, as I was emptying my wallet quite regular. It got down as low as 15.4 l/100km sitting on 90kph. I'd kill for 11's. So what are Gen3 injectors precisely, also do these injectors impact across all driving conditions?

Rob

[Rupert Prior]

they have allways been known for being a motor that likes a drink and the gas fittment will upset the original setup. what model p38 do you have? there are a few things to check thermostat (should run in low to mid 90'sC) airflow meter, O2 sensors (if fitted) etc. gems i can lean off during tune up, but bosch has to have a new map. changing camshafts, upping compression and moving the injectors can help but is a lot of work. the first thing to do is get the original setup checked by someone you trust.

[Hoges]

I'll stick my neck out:angel: and offer the opinion that the numbers are not too bad!:wasntme: weight and aerodynamic drag are the biggest killers of fuel economy. As Rupert has also pointed out, having the option of running on gas means that the vehicle is not optimised for petrol...

Once you exceed about 80kmh the drag increases according to the inverse square law... double speed means x4 times drag... so you have x9 drag at 90kmh vs 30kmh etc. Carrying a roof top tent, spare fuel containers etc means that your drag coefficient is high to begin with. Add to that approx. 3/4 tonne payload, roughroads etc and you're heading into small tray truck equivalents. The V8s were/are virtually all of the low compression variety and so while they are under stressed, they are also much less efficient..

I've been wrestling with this also (1999 Bosch 4.6) . A rough cost benefit to get an improvement of say 4L/100 km equates to $6 (say $1.50 /litre) or 6c/km. A $7000 "fix" to achieve this equates to about 116, 000 km to break even at today's prices ....

I've concluded it's all too hard and so am concentrating on maintaining the vehicle in good condition and storing as much as possible inside, taking as little as possible and driving 'sedately'... last trip to Sydney with 4 adults and luggage ...about 10.5 hrs actual driving time each way... a shade over 12.2 L/100km.
FWIW... a cousin recently traded his Audi Q7 3L Tdi on a new LC 200 diesel (after a confrontation over a $12, 000 repair demand for a new fuel pump ...only a couple of months after warranty expired..).. anyway, his Toyo gets about 11.8 on the hwy unloaded and 17-18 loaded with camping gear ...roof rack etc

[Robsrod 58]

they have allways been known for being a motor that likes a drink and the gas fittment will upset the original setup. what model p38 do you have? there are a few things to check thermostat (should run in low to mid 90'sC) airflow meter, O2 sensors (if fitted) etc. gems i can lean off during tune up, but bosch has to have a new map. changing camshafts, upping compression and moving the injectors can help but is a lot of work. the first thing to do is get the original setup checked by someone you trust.

Rupert,

I just put Hawkeye on Hoover and " fault code 18 O2 probe missing or intermittent bank 2 ".

I had this fault about 6 months ago, and G. Coopers changed the sensors. MMM maybe not the sensors as the fault will clear but returns on engine start.

P.S 2001 Thor, new cooling system .

[Robsrod 58]

I'll stick my neck out:angel: and offer the opinion that the numbers are not too bad!:wasntme: weight and aerodynamic drag are the biggest killers of fuel economy. As Rupert has also pointed out, having the option of running on gas means that the vehicle is not optimised for petrol...

Once you exceed about 80kmh the drag increases according to the inverse square law... double speed means x4 times drag... so you have x9 drag at 90kmh vs 30kmh etc. Carrying a roof top tent, spare fuel containers etc means that your drag coefficient is high to begin with. Add to that approx. 3/4 tonne payload, roughroads etc and you're heading into small tray truck equivalents. The V8s were/are virtually all of the low compression variety and so while they are under stressed, they are also much less efficient..

I've been wrestling with this also (1999 Bosch 4.6) . A rough cost benefit to get an improvement of say 4L/100 km equates to $6 (say $1.50 /litre) or 6c/km. A $7000 "fix" to achieve this equates to about 116, 000 km to break even at today's prices ....

I've concluded it's all too hard and so am concentrating on maintaining the vehicle in good condition and storing as much as possible inside, taking as little as possible and driving 'sedately'... last trip to Sydney with 4 adults and luggage ...about 10.5 hrs actual driving time each way... a shade over 12.2 L/100km.
FWIW... a cousin recently traded his Audi Q7 3L Tdi on a new LC 200 diesel (after a confrontation over a $12, 000 repair demand for a new fuel pump ...only a couple of months after warranty expired..).. anyway, his Toyo gets about 11.8 on the hwy unloaded and 17-18 loaded with camping gear ...roof rack etc

Hoges,

Thats quite thought provoking.
To have so much on the roof is not ideal, I agree. The main concern, I guess, knowing that I will never recover my costs incurred with this car I'm prepared to invest a bit more, keep it longer and enjoy. My hope is I will gain extra range without having to tow a tanker behind.

Anyway I'll have to address the O2 issue first.

Rob

[Hoges]

Hoges,

Thats quite thought provoking.
To have so much on the roof is not ideal, I agree. The main concern, I guess, knowing that I will never recover my costs incurred with this car I'm prepared to invest a bit more, keep it longer and enjoy. My hope is I will gain extra range without having to tow a tanker behind.

Anyway I'll have to address the O2 issue first.

Rob

Towing a tanker is exactly what I did a couple of yrs ago... 250L transport tank from a new MB prime mover lives on the draw bar of my DIY camper trailer:angel::eek: only filled once we are about to leave the bitumen....:twisted:

[wayneg]

Not 100% sure on this but think I am right. The Gen 3 Bosch injectors are a direct replacement for the Lucus injectors on Gems cars. I have swapped them on a Classic with good results. The Thor engine I presume would already have the Bosch injectors.
Anyone looking to do the swap get onto ebay and search for Ford 19lb injectors. They are all yellow in colour. I sorted a set last week for a friend and they cost US$60 + Shipping for a full set of 8 used but ultrasonic cleaned, flow tested with new o rings and pintile caps. They look different from the Lucas but are a direct plug and play replacement

https://www.aulro.com/afvb/images/imported/2013/08/1070.jpg

[Hoges]

The Thor engine has "green" Bosch injectors...
My first thought is, depending on how many km you have on the clock, is to remove the injectors and get them professionally cleaned and calibrated. There's a bloke in Bris. who has a van set up like a flow laboratory and provides this service. He did mine abhout 2 yrs ago ...about $25 per injector, ultrasonically cleaned, checked, tested, calibrated, new o-rings... there's probably a similar service in Sydney. took about an hour all up. Well worth it.... better than >A$100 ea for new! Once you have altered anything like new O2 sensor / MAF /injectors etc don't forget to get the adaptive values for the EFI mapping reset. ...

[Rupert Prior]

i think that code is being caused by the gas installation also using the o2 sensors, also sometimes they fit different sensors for the gas as the voltage is wrong for their system. if you are in the Bexley area sometime i can check the live data with Testbook.

[TheTree]

Hi,

Reading this with great interest, since i am currently getting a "Left Bank too lean" message.

I think cleaning my MAF is in order

Steve

[TheTree]

Hi

Just a quick note on this, I was reading this thread about adaptive values and it is has some interesting info about airflow rates etc

http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/22296-adaptive-values-reset-2.html

Essentially it seems the things to check before you mess about with anything are

1) Coolant temp should be in in low-mid 90's Mine seems to run around 93-95

2) MAF should be cleaned

3) TPS should be checked

4) Vacuum hoses need to be checked for air leaks

Steve

[frantic]

Just to give some perspective. I had 2 prados previously, both on LPG, the older one had the old style system and was around 15-16l /100k's the 03 we had fitted with LPG injection and was 12-14 loaded with 2 adults, 3 littlies , full boot,but nothing on roof, gong to gold coast.This is on a 4.0 v6 that way loaded would still be 500 kg lighter and not as nice to drive as a RR with a 4.6. So along with the 20% weight penalty you've also got heavy drag with a roof rack full and are only using 20% more fuel, not to bad. :)

[Robsrod 58]

Ok,
Just spoke to Ward of Graeme Cooper Auto in Sydney, he is saying that 17.2 is pretty good for what I had on board ( mirrored your comments Hoges ).

He also said that you could gain a little from free flowing cats and minor remapping of ECU, but essentially what you see is what you get from this vintage V8 ( Thor with 193000km ). Anyway he's going to have a look at whats going on with the O2 sensor on Thursday

Thanks Rupert for your offer, I'm at Engadine not too far from you, and I feel your services will be required at some point of my ownership!

Having said that I noticed another post on fuel economy when towing a trailer has just popped up, I'll be watching with interest.:confused:

[benji]

Missed the bit about the roofrack. When we had the classic we were looking at a roof top tent, but after a trip with swags on the roof never again!

[Robsrod 58]

Missed the bit about the roofrack. When we had the classic we were looking at a roof top tent, but after a trip with swags on the roof never again!

Benji,

If your referring to me, see below.
The more I look at it, the more it looks like a massive wind break:(:(

Rob

[Hoges]

Great to see a P38 in its "natural" environment !! :D
A lightweight aerofoil to deflect the air flow over the roof rack would probably make a significant difference...

[Hoges]

Ok,
Just spoke to Ward of Graeme Cooper Auto in Sydney, he is saying that 17.2 is pretty good for what I had on board ( mirrored your comments Hoges ).

He also said that you could gain a little from free flowing cats and minor remapping of ECU, but essentially what you see is what you get from this vintage V8 ( Thor with 193000km ). Anyway he's going to have a look at whats going on with the O2 sensor on Thursday

Thanks Rupert for your offer, I'm at Engadine not too far from you, and I feel your services will be required at some point of my ownership!

Having said that I noticed another post on fuel economy when towing a trailer has just popped up, I'll be watching with interest.:confused:

PS. Does anyone have a long range fuel tank they don't need any more??

If he can remap the Thor ECU I'd be most interested... there was some discussion on this elsewhere but to the best of my knowledge...fed from reports of enthusiastic BMW forum posters whose late 90s 3-series had the same Motronic set up, it's virtually impossible to remap the ECU because the BMW engineers in league with the Bosch folk made it "very" proprietary to prevent virtually any other tune state:mad: added to which if it's altered more than a dozen or so times, ...for example make a change save, rewrite save etc as you do with incremental changes... the ECU miraculously assumes the guise of a "brick" !! Which raises the question as to whether some smart cookie might be able to adapt the tuneable GEMS architecture to a Thor engine for improved performance taking advantage of the Thor manifolds which I'm told improve low end torque....

[Robsrod 58]

Hoges,
Stay tuned, I have more questions about that myself.
And to think I was a bit apprehensive about going on my own, especially after seeing 2 x nissans on flat beds going back to Broken hill from Tib worse for wear
A lot of k's still on 18's, 2 spares and not 1 puncture. Just ask me if I like "General Grabbers":D:D:D

Rob

[Hoges]

On a trip a couple of years ago... minimum load, steady speed, no load on roof rack...

https://www.aulro.com/afvb/images/imported/2013/08/966.jpg (http://s1157.photobucket.com/user/chopperdoctor1/media/23-10-10_1631_zps404aaa95.jpg.html)

[rangieman]

Are you joking :p You dont buy a V8 petrol 2 ton + 4x4 with the aero dynamics of a block of flats and then complain about fuel economy . What were you thinking :angel:

[Robsrod 58]

On a trip a couple of years ago... minimum load, steady speed, no load on roof rack...

https://www.aulro.com/afvb/images/imported/2013/08/966.jpg (http://s1157.photobucket.com/user/chopperdoctor1/media/23-10-10_1631_zps404aaa95.jpg.html)
Hoges, Is this some white man magic I see:p:p:p

[benji]

Not really. I got 11.4l at 110 on the calder a fortnight ago, but come to a hill or go throughout a town and that average quickly climbs to 13ish. A spot fuel measure is quite different to an average.
I think the main issue with Rob's figures is the roofrack.

[TheTree]

Hi,

My dash figures are double that , but i think that is more to do with the fact it runs on LPG, but it still chews around 22l/100K on LPG.

Tune up time for me I reckon !

Steve

[davidsonsm]

Anybody got any further opinions on the pros and cons of the bosch injector change for the gems engine? Whether the change is notable and meaningful?

[cal415]

Very interested in the injector change too, mine is averaging around 20l per 100km general driving with a fair ammount of highway in there.. its terrible.

[wayneg]

Watch the vid and make your own mind up if you think its worth trying out a US$60 set of refurbished Bosch 3`s

comparison of Lucas type disc injector to Bosch design III to the stock GM multec. - YouTube

[Hoges]

Hi,

My dash figures are double that , but i think that is more to do with the fact it runs on LPG, but it still chews around 22l/100K on LPG.

Tune up time for me I reckon !

Steve

LPG is a mix of butane (mostly) and propane. ULP is a mix of hydrocarbons which have molecules virtually double the length of LPG hydrocarbons... and for the sake of argument, twice the energy per unit volume... so for an engine with about the same efficiency, you might get about twice the distance from ULP than from the same volume of (liquid) LPG.... so 22L/100km is probably around the mark depending on driving conditions etc.

[wanglemoose]

Watch the vid and make your own mind up if you think its worth trying out a US$60 set of refurbished Bosch 3`s

comparison of Lucas type disc injector to Bosch design III to the stock GM multec. - YouTube (http://www.youtube.com/watch?v=7oTirEZNRw8)


btw none of those are the same as the gems ones. the spray pattern from the originals is a straight squirt. originally when i put mine in the bench i thought they were stuffed so i tested a brand new one to find exactly the same spray pattern, there is almost no atomization in them at all. changed to the bosch ones and fuel economy went from 17 l/100 highway to 12 l/100. torque also increased with the change. on another note these engines are a very dirty running engine i would suggest doing a carbon clean too.

[Hoges]

There's been a deal of discussion on Range Rovers.net replacing the Lucas injectors in the GEMS engine with Bosch and other injectors originally specified for the Ford Mustang see also Bosch 4.6L V8 Fuel Injectors (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/46890-bosch-4-6l-v8-fuel-injectors.html) and scroll down to post #4 for more detail ...hope this helps

[wayneg]

btw none of those are the same as the gems ones. the spray pattern from the originals is a straight squirt. originally when i put mine in the bench i thought they were stuffed so i tested a brand new one to find exactly the same spray pattern, there is almost no atomization in them at all. changed to the bosch ones and fuel economy went from 17 l/100 highway to 12 l/100. torque also increased with the change. on another note these engines are a very dirty running engine i would suggest doing a carbon clean too.

I have only done the change on a 3.9 classic but got good results most notably smoother running and mid range acceleration .
This vid might be better to show the non atomization of the Lucas
comparison bosch 24 multec lucas bosch3 bosch yellowtop bosch22 - YouTube

[cal415]

Anyone know part no's? i would like to give these a try in mine.

[jsp]

hmmmm new injectors could be good.

But I still have to think 17l/100 for a fully loaded P38 with stuff on the roof on mixed roads is actually pretty good.

When mine was young and spritely I would do Adelaide melb trips and get in the 12's.

[cal415]

how about 20l/100km ULP for unladen p38 mainly on the highway.... definetly something up there i think.

[wayneg]

Anyone know part no's? i would like to give these a try in mine.


19lb Fuel Injectors Mustang Camaro Corvette Set 8 | eBay (http://www.ebay.com/itm/19LB-FUEL-INJECTORS-MUSTANG-CAMARO-CORVETTE-SET-8-/171099886383?pt=Motors_Car_Truck_Parts_Accessories&hash=item27d659132f&vxp=mtr)

[cal415]

19lb Fuel Injectors Mustang Camaro Corvette Set 8 | eBay (http://www.ebay.com/itm/19LB-FUEL-INJECTORS-MUSTANG-CAMARO-CORVETTE-SET-8-/171099886383?pt=Motors_Car_Truck_Parts_Accessories&hash=item27d659132f&vxp=mtr)

Thanks, are these the same as some have used ok the 3.9 discos? If so I will get 3 full sets as I have 2 3.9s as well

[justinc]

Thanks, are these the same as some have used ok the 3.9 discos? If so I will get 3 full sets as I have 2 3.9s as well

AFAIK yes they are compatible.


JC

[cal415]

Cool thanks i will order a few sets and see how they perform, how hard is the swap? taking a quick look at the motor i assume the top of the intake needs to be taken off?

[Hoges]

Hoges, Is this some white man magic I see:p:p:p

It was an "Average" over about 700 km section of a 2600+ km return Bris-Canberra trip. I was attempting to see just what might be possible...I filled up on the Newcastle expressway at that large service centre (Ourimbah?) on 95 oct. to the first "click" on the pump, and did not reset the trip meter etc. drove to Canberra then filled up again ...it was freezing cold... then topped up again at Pennant Hills on the way home. I snapped the photo somwhere on the Pacific Hwy near the Gosford turnoff ...I think. It was early evening, the weather fine and chilly and the temp was just on the "dew point" ...so the air/fuel charge was optimum. further the temp of the fuel in Canberra and Pennant Hills was such that I probably got a decent density...i.e. more mass of fuel per litre than on a hot day where the fuel can expand by 20% or more...and servo pumps are NOT to my knowledge corrected for temperature... (in the same way, notice when pilots talk about refuelling large aircraft they usually speak in terms of taking on "X" lbs of fuel" not necessarily litres/gallons...

A pump volume/GPS distance calculation ultimately came to a shade under 11.5 L/100km for the whole trip.

NOTE: I only do these "experiments" when driving without the co-driver to amuse myself :eek: oh yes and wave to other LR vehicles irrespective of model... ;)

[Hoges]

Cool thanks i will order a few sets and see how they perform, how hard is the swap? taking a quick look at the motor i assume the top of the intake needs to be taken off?

Which engine? If it's a Thor, you need to drain a few litres of coolant and remove the top inlet manifold... this entails a fair amount of work but it's straightforward ...RAVE is your friend. Also check PaulP38's website for pics. One tricky bit is disconnecting the fuel rail from the flexible fuel line...
Take a lot of photos and seal bits in clip lock plastic bags with labels inside the bag ...including a rough sketch as to how / where they fit...sometimes photos are not enough:angel:

It's going to be a long exercise if you're going to do a DIY comparison between different sets of injectors... but you'll certainly be an expert in dismantle/replace!
One more thing: there's a metal gasket required between the upper manifold and inlets on the Thor engine. Get a replacement and smear it both sides (clingwrap thickness only!) with Locktite 518 to ensure an airtight seal.

Good luck with it!

[DANMAL]

Hi all, been really interested in this thread as I'm due for an injector clean.. just wondering if these injectors are the same as mine in my 99 Thor motor, not sure if I should get mine cleaned or purchase these ones... which ones are better,any advice would be much appreciated. .
Cheers
Sam

[DANMAL]

Sorry forgot to mention it's a 4.6ltr

[Robsrod 58]

Ok,

Follow up on "fault code 18 O2 sensor error", turns out to be a faulty iridium spark plug missing causing O2 sensor not being able to measure oxy on that particular firing point, hense a fault sensed.

Its funny how I couldn't feel the miss on 1 cylinder but when Its fixed Its so much smoother

All plugs replaced with platinium type, they reckon their more reliable.

Thats more wasted money on my part, as I put the iridiums in the car in the first place:mad:

No further info on remapping of ECU as the guys were really busy when I picked the car up.

Rob

[Hoges]

Hi all, been really interested in this thread as I'm due for an injector clean.. just wondering if these injectors are the same as mine in my 99 Thor motor, not sure if I should get mine cleaned or purchase these ones... which ones are better,any advice would be much appreciated. .
Cheers
Sam

Unless you have real proof that your injectors are suss, my advice fwiw is to run the tank down to a bit less than quarter full, pour in a bottle of injection cleaner and then fill tank with 98 oct. Take it for a long run...I mean several hundred km:D then see if it's improved...or not and then plan yr next move...the std "green" Bosch injectors in the Thor 4.6 are (normally) very reliable.
Cheers

[cal415]

Which engine? If it's a Thor, you need to drain a few litres of coolant and remove the top inlet manifold... this entails a fair amount of work but it's straightforward ...RAVE is your friend. Also check PaulP38's website for pics. One tricky bit is disconnecting the fuel rail from the flexible fuel line...
Take a lot of photos and seal bits in clip lock plastic bags with labels inside the bag ...including a rough sketch as to how / where they fit...sometimes photos are not enough:angel:

It's going to be a long exercise if you're going to do a DIY comparison between different sets of injectors... but you'll certainly be an expert in dismantle/replace!
One more thing: there's a metal gasket required between the upper manifold and inlets on the Thor engine. Get a replacement and smear it both sides (clingwrap thickness only!) with Locktite 518 to ensure an airtight seal.

Good luck with it!
Mine is a 96 GEMS 4.6, towing a small 6x4 box trailer on the highway over the weekend, i didnt really notice the weight of the trailer behind it because it always feels sluggish, but cruising along about 90-100kph i was using around 19l per 100km, this seems excessively high considering it was such a small trailer and i was driving it as conservatively as possible.

The motor seems healthy enough, doesn't seem to miss at all, doesn't use coolant or burn much oil, but it is definitely sluggish and thirsty. The only other sign i have had of an issue is a very very brief hesitation when it first starts, it turns over then coughs and comes to life straight away occasionally, apparently it has done this and stalled on my wife before too.

[mtb_gary]

CAL415
Those fuel consumption figures look terrible! Without the trailer do you normally experience such bad figures? If your fuel consumption is considerably less without the trailer, check the bearings on the trailer, you may find they are in need of replacement.

Gary

[cal415]

not much better(possibly almost the same) without the trailer... it just guzzles the juice, it smells very rich at idle too i have noticed.

[mtb_gary]

Cal415

Certainly worth checking out the usual list, filters, spark plugs, spark plug leads, MAF etc. Also maybe check to see if the choke is remaining partially on?

Gary

[RobboLFC]

I am looking at pulling out dash and changing heater matrix and o rings. Plus I will be draining the engine of oil and replacing leaking oil cooler hoses in the next few weeks. Would it be worthwhile changing to these injectors while doing this work? Currently I am doing about 19Lt/100KM which is way too high. I run 255/65R/16 tyres all round with 28 psi up front and 38 psi down back as per factory instructions.
Currently I am getting about 500km per full tank of fuel not running on lpg, when I fill up I usually have about 5Lt left in tank.
My car is a 1996 4.0SE everything else on the car is stock.

[Keithy P38]

That's insane! Even around town ill get 550km before the fuel light says hello! And when I fill its usually 80 litres that goes in... On average ill fill at 600kms, sometimes more, sometimes less... I think I worked it out to be a 15L/100km town average and 12L/100km highway average.

That's a Bosch 4.6 with 240,000km.

If you want to do something to the injectors and don't change them, I'd be getting them professionally cleaned at least!

That said, is there another aspect of your motor that may also be contributing to the high fuel consumption?

Cheers
Keithy

[RobboLFC]

That's insane! Even around town ill get 550km before the fuel light says hello! And when I fill its usually 80 litres that goes in... On average ill fill at 600kms, sometimes more, sometimes less... I think I worked it out to be a 15L/100km town average and 12L/100km highway average.

That's a Bosch 4.6 with 240,000km.

If you want to do something to the injectors and don't change them, I'd be getting them professionally cleaned at least!

That said, is there another aspect of your motor that may also be contributing to the high fuel consumption?

Cheers
Keithy


I agree it is insane. I put the car in to a well known workshop for Landies here in Perth and they said there was no issues with the car.
I knew it was high but just thought it was normal for Range Rovers having never had one before. I run injector cleaner fluid about every six months but that only makes a little bit of a difference but not much.

[Offender90]

I agree it is insane. I put the car in to a well known workshop for Landies here in Perth and they said there was no issues with the car.
I knew it was high but just thought it was normal for Range Rovers having never had one before. I run injector cleaner fluid about every six months but that only makes a little bit of a difference but not much.

Wouldn't be a workshop south of the river, in a suburb starting with the second letter of the alphabet by any chance, would it?

[RobboLFC]

... ;)

[Offender90]

Lovely chaps...

http://www.aulro.com/afvb/technical-chatter/46163-3-9l-v8-heat-normal.html

... post 30 is the reason I'm my own mechanic these days! ;)

[Hoges]

not much better(possibly almost the same) without the trailer... it just guzzles the juice, it smells very rich at idle too i have noticed.

If you can smell fuel I'd also have a good look at the fuel pressure regulator and for leaks in the fuel delivery hose before it joins the fuel rail...

[cal415]

Definetly no leaks but it is running very rich, it seems to have taken a turn for the worse again, last tank was about 320km, but that included a bit of off roading but not heaps.... whats the best method for checking fuel pressure reg on one of these?

[Hoges]

Hi cal415
I doubt there's any simple way to test the fuel pressure regulator other than replace it with a known serviceable item and check for a difference in performance... damned expensive option however for a "yes/no" answer!:( last check (GEMS) was about $180+ locally for said unit... Unlike the GEMS engine where the regulator is reasonably accessible on the driver's side of the engine, the Thor engines have the regulator incorporated in the pump assembly ...in the tank.

EDIT: just had a thought :eek: .. the injectors may be quite OK. It's running rich because the injectors are being "commanded" to let in more fuel by the ECU. The ECU calculates oxygen content of the air as determined by the MAF taking account of the ambient temperature as well as fuel temp.

The ECU "thinks" that there's too much air i.e the air/fuel mix is running "lean" so it's enriching the mix accordingly. The fuel odour at idle tends to confirm this. I 've only had a cursory glance at the posts to date, but MAF and air/fuel temp. sensors don't seem to have been discussed. The sluggish engine response you reported is one symptom of a MAF needing attention. It might just require a squirt of MAF cleaner to remove accumulated crud off the sensor wire (non-residue disc brake cleaner will perform the same job at a pinch DON'T USE WD40!!)... careful, the sensor wires are fragile.

Have a look here for details and pics of how to , on a GEMS set up http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/30844-cleaning-gems-maf-mass-airflow-sensor-pics.html

Check the temp sensors also for proper connection. Have a look also as to whether there's any accumulation of oil in the throttle body housing... i.e. the PCV set up may also need attention.

Good luck with it..!

[Dougal]

I don't have a 4.6, but on other EFI engines (petrol or diesel) disconnecting the MAF forces the ECU to use lookup tables for what the airflow is expected to be based on throttle and rpm.

If the engine gets better with the MAF unplugged, then it's time to look harder at the MAF. If there's no difference, then look elsewhere.

[cal415]

unfortunately this will have to go on the back burner for a few week, i leave for cape york thursday next week and it will be a mad rush before hand getting the defender ready.. but i will have a play if i get a chance.

[Hoges]

Enjoy the trip and happy travelling:D

[Keithy P38]

I just got back from the cape mate, was a great trip!

Words of wisdom from me - Take the tele track north and take the northern section of the tele south, the bypass road for the northern section has corrugations the size of speed humps. The rest of the developmental road was good. We went through Lakefield both north and south as the developmental road in that section is also pretty bad from what we heard.

None of the creek crossings stopped us, but last count was 88 vehicles drowned this year at Nolan's brook. The Frenchmans track is also worth a look if you have a day to do it.

Enjoy your trip!

[benji]

EDIT: just had a thought :eek: .. the injectors may be quite OK. It's running rich because the injectors are being "commanded" to let in more fuel by the ECU. The ECU calculates oxygen content of the air as determined by the MAF taking account of the ambient temperature as well as fuel temp.

The ECU "thinks" that there's too much air i.e the air/fuel mix is running "lean" so it's enriching the mix accordingly. The fuel odour at idle tends to confirm this. I 've only had a cursory glance at the posts to date, but MAF and air/fuel temp. sensors don't seem to have been discussed. The sluggish engine response you reported is one symptom of a MAF needing attention. It might just require a squirt of MAF cleaner to remove accumulated crud off the sensor wire (non-residue disc brake cleaner will perform the same job at a pinch DON'T USE WD40!!)... careful, the sensor wires are fragile.


Yeh, that. You're on the ball Hoges.
Gems will run off of lookup tables with no maf. It uses the air temp and throttle position sensor.

If it still won't play cricket it may be the fuel return pipe is blocked.

All the best for the Cape, im jelous everytime I hear of someone going up there (cough...Kiethy:mad:)

It's almost the wet season though isn't it?

[Keithy P38]

Still got two months til the rains up that way!

Everyone should go!

[cal415]

Planning on doing the Tele track travelling north and definetly doing frenchmens, the defender is going to be pretty well setup but i will be towing a camper through a lot of it, also really keen to check out old coach road. how did you go with the camp site booking system up there?

[Keithy P38]

You'll get a camper through the tele no worries, Frenchmans is a bit tight but you can still get a trailer in if you take it easy! Old coach road is slow and rough - hope your camper trailer has good clearance! Maytown is a nice little place to check out, plenty of history in that area.

We booked as we went. In Lakefield we booked at the ranger station for a night at Kalpowar (the only decent spot other than the Laura river that's actually a nice camp site). Be warned - Optus or anything other than Telstra is virtually not covered up that way. At the ranger stations you get Telstra, anywhere in between Laura and the top it's weipa, Coen and then the tip that you get Telstra, everywhere else is sat phone country. Even the roadhouses are without mobile coverage but they do have pay phones.

Everywhere else we just played it by ear and booked as we rolled in the driveways. Plenty of accommodation provided its not school holidays.

Archer river roadhouse was about the busiest place we stayed other than the Punsand bay resort (more a glorified camp ground than anything).

Take a spare oil filter - my mate didn't and it was very lucky ours were interchangeable and I had a spare. Plus all the other usual spares.

If it is school hols when you are up there (which I think it might be), I'd be pre-booking. They are pretty flexible if you are a day ahead or behind provided you call up and let them know. Many travelers we spoke to were either in front or behind and mentioned that.

If you have a wife/partner traveling with you I can give GPS coordinates of all the drop toilets along the way if you like ;-) and if you want my number feel free to pm me - if you run into drama, any excuse for me to get back up there is a good one and I can get as far as weipa in a days drive, would be able to make the tip in two if I pushed! That means the Frenchmans track is only a day away for me (never thought of it like that before)!

Cheers
Keithy