Please Need Advice Vn 90 model bad fuel economy

[aussieghostrider]

Gday, Sorry for the long post but im out of ideas.....

I have had my car since it rolled out the factory, i change oil every 5000km's with filters as well etc,its got 180,000km's on it,has original engine,gearbox,diff etc which are serviced,injectors cleaned properly,K&NPod filter and irdium spark plugs that cost $14 each,also has reasonable new leads,Cars also had respray and 2.5 sports exhaust fitted with new CAT.

Ive had the water pump replaced 4 times,crank sensor once,and the coolant bottles replaced cause they cracked from age/heat & also replaced the oxygen sensor 3 times so far which ive taken off the battery lead to reset the computer,also Fuel pumps been replaced one time & The starter motors been replaced 2 times.

The car starts/idles fine & revs hard & goes hard off the line and does not even blow one wiff of smoke and the car doesnt use one drop of oil either.If you look underneath the car theres a little oil/dirt but thats to be expected and gets washed away when im cleaning the car,the power steering leaks a little but i use that nulon power steering stop leak and that does the job plus i tightened up few hoses around the engine,Basically im trying to explaing the cars in 100% good condition as far as i know and im going to get new suspension all round fitted in next few weeks.

But my main concern is trying to get better fuel economy as ive done everything i can think of.. now i have these options and i would like your help in deciding what to spend $$$ on to fix this problem as fuel prices arent the best these days...Im getting around 300-350km's city driving from a completly full tank,If i go freeway driving i do get better economy. Ive had the oxygen sensor replaced in last 5 months.The car does use a little coolant but i think its from evaporation over time.Ive gone over the fuel lines to check for leaks but nothing.The only thing i notice is the car is definately running Rich as i can smell petrol smell from exhaust.Can the fuel Regulator be stuffed but not leak into vacum line ?? as i checked it and no petrol.I also run Nulon injector cleaner every 3rd tank.

These are my options or any other ideas would be appreciated...

1.New Fuel Regulator

2.Get Extractors ( As original ones crack)

3. ?????


Any ideas or help please or am i getting the best i probably can ? as ive read many posts saying i should be getting 400km's+ city driving from a full tank??

heres photos of my beast...
http://img.photobucket.com/albums/v7...ules/mycar.jpg

http://img.photobucket.com/albums/v7...les/engine.jpg

http://img.photobucket.com/albums/v7.../podfilter.jpg

Thankyou...

[andy05]

Gday, Sorry for the long post but im out of ideas.....

I have had my car since it rolled out the factory, i change oil every 5000km's with filters as well etc,its got 180,000km's on it,has original engine,gearbox,diff etc which are serviced,injectors cleaned properly,K&NPod filter and irdium spark plugs that cost $14 each,also has reasonable new leads,Cars also had respray and 2.5 sports exhaust fitted with new CAT.

Ive had the water pump replaced 4 times,crank sensor once,and the coolant bottles replaced cause they cracked from age/heat & also replaced the oxygen sensor 3 times so far which ive taken off the battery lead to reset the computer,also Fuel pumps been replaced one time & The starter motors been replaced 2 times.

The car starts/idles fine & revs hard & goes hard off the line and does not even blow one wiff of smoke and the car doesnt use one drop of oil either.If you look underneath the car theres a little oil/dirt but thats to be expected and gets washed away when im cleaning the car,the power steering leaks a little but i use that nulon power steering stop leak and that does the job plus i tightened up few hoses around the engine,Basically im trying to explaing the cars in 100% good condition as far as i know and im going to get new suspension all round fitted in next few weeks.

But my main concern is trying to get better fuel economy as ive done everything i can think of.. now i have these options and i would like your help in deciding what to spend $$$ on to fix this problem as fuel prices arent the best these days...Im getting around 300-350km's city driving from a completly full tank,If i go freeway driving i do get better economy. Ive had the oxygen sensor replaced in last 5 months.The car does use a little coolant but i think its from evaporation over time.Ive gone over the fuel lines to check for leaks but nothing.The only thing i notice is the car is definately running Rich as i can smell petrol smell from exhaust.Can the fuel Regulator be stuffed but not leak into vacum line ?? as i checked it and no petrol.I also run Nulon injector cleaner every 3rd tank.

These are my options or any other ideas would be appreciated...

1.New Fuel Regulator

2.Get Extractors ( As original ones crack)

3. ?????


Any ideas or help please or am i getting the best i probably can ? as ive read many posts saying i should be getting 400km's+ city driving from a full tank??

heres photos of my beast...
http://img.photobucket.com/albums/v7...ules/mycar.jpg

http://img.photobucket.com/albums/v7...les/engine.jpg

http://img.photobucket.com/albums/v7.../podfilter.jpg

Thankyou...

I think 300-350kms is not bad. People who claim more may drive under different conditions. Their feet may not be so heavy. But seriously I only get about this much, and I'm not too concerned. I'm surprised though the respray did'nt improve your economy at at all I've heard the camber of the front wheels can get out out whack with age, and this can increase fuel consumption. My VN is doing this, wearing out the inside tread of the tyre. Am thinking of getting a camber kit to fix this.

[WaynoVN]

Well your car sure looks in smick condition and from what you've explained I can see why. I can't help with your prob mate, I have a 88 V6 manual and get around 600k's to every tank. I drive 120k's a day to work and back, 18 sets of traffic lights, a few 110k/h sections and I drive pretty hard. But in saying this I have done pretty much the same as you. Regular oil change / service, always fresh plugs, fuel treatments (not as often as you though) CAI, K & N filter, new O2 sensor, new TPS sensor and extractors and 2.5" zorst.

[andy05]

Well your car sure looks in smick condition and from what you've explained I can see why. I can't help with your prob mate, I have a 88 V6 manual and get around 600k's to every tank. I drive 120k's a day to work and back, 18 sets of traffic lights, a few 110k/h sections and I drive pretty hard. But in saying this I have done pretty much the same as you. Regular oil change / service, always fresh plugs, fuel treatments (not as often as you though) CAI, K & N filter, new O2 sensor, new TPS sensor and extractors and 2.5" zorst.

I noticed my VN does well at about 100+ kms an hour too.

[aokman]

When i got mine i got 280 to a tank at best, after i replaced my fuel regulator, oxy sensor and coolant sensor i got it up to 420km a tank gunning it everywhere, in my case it was the fuel regulator that was faulty. There was no fuel in the vaccum line but it stunk of fuel. These days however i get about 350 with my wade 992a cam.

If you want to put another stock regulator in, go to a wreckers and get a fuel regulator from a VR engine and also grab the fuel dampner off it as it was added in the VR models, its just under the trottlebody plate, dont bother buying a new stock regulator, will be $150+ and you'd be better off with an ajustible one from ebay thats cheaper.

[fazz1977]

Fuel regulator huh... hmmm, pics?

[nopatcla]

Hi Guys

Before you get too worked up about fuel consumption, find out what you are actuallyb getting in km's to litres, fill up the tank and set the trip meter to zero, and then drive until empty, fill up again and divide the no of km's by the no of litres, I get around 10.5 to 11 km per litre on the open road and bout 8 km per litre around town. Never go by the gauge as they are not accurate.

Nobby

[aussieghostrider]

ok My economy is total crap at moment ... I filled the car up a week ago and when i say fill it up i mean so that fuels coming out thats when i stop filling.
Now i got 200km's and my fuel guage says i got 1/3 of a tank left,My o2 sensor has obviously shit itself again.
The gauge i do have to hit it to get it to move but once i give it a tap it goes all the way and moves fine. I have driven the car till its in the red and i know that the guage is reading ok casue the car runs like shit when its nearly dry.

Ive read that the manifold on the passenger side of all the Vn v6's CRACK with age,now the o2 sensor is on that side so if i had a small crack in the manifold which was leaking coolant could it cause the o2 sensor to corrode and die quickly ???


As this is the only thing i can think of thats happening..

I dont have a cracked head as the cars never been overheated... and theres no milky oil etc

Are there Any Mechanics or Exhaust fitters out there heard of this problem ??

The o2 sensor is less than 6 months old and looks like brand new still...

[mouce]

A healthy manual VN with a 'sensible' driver around town should be able to get 10-11l/100km if you really want to. I've managed to get under 10 a couple of times. An auto will typically use one or two litres more per 100km. Out on the open road, if you're 'sensible' it's possible to get it down to 7L/100km (manual) and about the same for the auto.

Biggest tip for fuel consumption. Keep your tyres hard. Holden recommend a very 'soft' tyre, as this is good for comfort, but wears your tyres faster, and chews a bit more fuel. I've got 14" stockies on it and they all run at about 36psi. Firmer ride, but much better fuel figures.

[VNPOWER]

A healthy manual VN with a 'sensible' driver around town should be able to get 10-11l/100km if you really want to. I've managed to get under 10 a couple of times.
.

How do you work this out?
Holden said they did around 12.5L /100k's and that was when they were brand new! so i doubt they get less or even match that 16 years later.

Out on the open road, if you're 'sensible' it's possible to get it down to 7L/100km (manual) and about the same for the auto .

mate, brand new hyundai Getz 4 cylinders get that, if you think a 16year v6 vn can do the same, you're dreaming.

[mouce]

Mate...I've got three years of fuel figures on my car, and the motor is STOCK, and it's got those figures. I'm not saying that EVERY VN will do it, but they are more than capable of it.

[VNPOWER]

wot a joke. Ive heard it all now, mouce's 16year old V6 VN gets the same economy as a modern 4 cylinder.

This is you dreaming --->

[nathans1987]

work out oyur kilometers per liters you do. i used to think mine was doing bad them i fixed my odometer and found out that it was not as bad a i thought. 10.5km/L.

[nathans1987]

mouse said that his country driving is the same as a 4 not city you are compairing vn country to 4 city. and i get the same as him

[aokman]

On a freeway theres no reason a VN cant do 8LT/100, ive done it a few times

[fazz1977]

My VP V6 Auto gets 14.8l per 100kms, 100% city driving, and a few silly moments per week. So a bit above normal, but certainly not terribly bad. Before CAI and K&N I was getting about 16-17l per 100kms. I run my car with tyres at 34psi too. Might kick up to 35, see how that goes,

[mouce]

Keep in mind that those figures that I quoted are for 'sensible' driving. If I really drive it like I want to all the time, it's not uncommon for me to see 13L/100km around town and about 10 on the open road.

And just for the record, she isn't 16 years old, she'll be 18 in August.

I've also managed to get my mum's excel to use 13L/100km out on the open road. So it all comes down to how you drive.

[coolvxss]

I get about 13L per 100km. 100% city driving. and i have a pretty heavy foot. if i take it easy i can get much better figures but whats the fun it that.

[andy05]

I get about 13L per 100km. 100% city driving. and i have a pretty heavy foot. if i take it easy i can get much better figures but whats the fun it that.

You're not wrong. I gotta take it easy round town all week, cause I'm a tight son of a B****, but on the weekend I have been known to do a little maintainance, including "cleaning out" the cylinders. This technique involves me flooring it a bit, but honestly its just to clean out the carbon deposits

By the way, if mouce is wrong, why do so many people on this site claim similar fuel consumption figures? I think the Holden figures were very "average". Average conditions, driving technique ect. Does'nt mean people can't do better than that, even 18 years later!

[Mr_Slim]

If you want to put another stock regulator in, go to a wreckers and get a fuel regulator from a VR engine and also grab the fuel dampner off it as it was added in the VR models, its just under the trottlebody plate, dont bother buying a new stock regulator, will be $150+ and you'd be better off with an ajustible one from ebay thats cheaper.

I have a problem with my fuel regulator and Holden Service told me i would need to buy another one new. Not the case?

They said that any 2nd hand one would already be stuffed...

Oh and to add further fuel to the fire (haha geddit?) my VP Calais has averaged 9.4L for the past month, with about 60/40 highway/city. I've just purchased CAI and its doing even better this tank...

[Murdoch]

A healthy manual VN with a 'sensible' driver around town should be able to get 10-11l/100km if you really want to. I've managed to get under 10 a couple of times. An auto will typically use one or two litres more per 100km. Out on the open road, if you're 'sensible' it's possible to get it down to 7L/100km (manual) and about the same for the auto.

Biggest tip for fuel consumption. Keep your tyres hard. Holden recommend a very 'soft' tyre, as this is good for comfort, but wears your tyres faster, and chews a bit more fuel. I've got 14" stockies on it and they all run at about 36psi. Firmer ride, but much better fuel figures.

This seems realistic if you drive sensibly.
I have babied my car for a full tank and managed 9lt/100km total city driving!
The v6's can ce economical if you treat them right.
Ill admit though, a granny could have accelerated away from the lights quicker than me when i got this figure

[andy05]

Hi Guys

Before you get too worked up about fuel consumption, find out what you are actuallyb getting in km's to litres, fill up the tank and set the trip meter to zero, and then drive until empty, fill up again and divide the no of km's by the no of litres, I get around 10.5 to 11 km per litre on the open road and bout 8 km per litre around town. Never go by the gauge as they are not accurate.

Nobby

Wonder if changing the wheel size (to presumably bigger) would make the odometer record less km's than you actually had done. After all, bigger wheels take longer to make one revolution. Just a thought. Yeah I know you can get 'em adjusted, but I'm sure a lot of us have'nt done that. For the record my odometer gives me a different reading on the exact same route home from work every night. Sometimes 3.8 km's , 3.9, 4.0, 4.4 he he Maybe its because sometimes I'm spinning my wheels

[sircruisealotVS]

ok My economy is total crap at moment ... I filled the car up a week ago and when i say fill it up i mean so that fuels coming out thats when i stop filling.
Now i got 200km's and my fuel guage says i got 1/3 of a tank left,My o2 sensor has obviously shit itself again.
The gauge i do have to hit it to get it to move but once i give it a tap it goes all the way and moves fine. I have driven the car till its in the red and i know that the guage is reading ok casue the car runs like shit when its nearly dry.

Ive read that the manifold on the passenger side of all the Vn v6's CRACK with age,now the o2 sensor is on that side so if i had a small crack in the manifold which was leaking coolant could it cause the o2 sensor to corrode and die quickly ???


As this is the only thing i can think of thats happening..

I dont have a cracked head as the cars never been overheated... and theres no milky oil etc

Are there Any Mechanics or Exhaust fitters out there heard of this problem ??

The o2 sensor is less than 6 months old and looks like brand new still...

it might not neccessarily be that the o2 sensor has crapped itself, but that the crack in the manifold is letting air in (and exhaust waste out) and this makes the o2 sensor "tell" the pcm to up the fuel, thus your runngin rich and gettin crap economy.

[savage1987]

Hmm. I'm having concerns now - my VN has come very close to redline temperature lately and I'm worried about the health of the engine. What typically fails at these sorts of temperatures?? I know I blew a tank on my radiator and I've replace that, but what about the rest of the engine?

I'm also noticing slightly worse fuel economy since then . . . And yes, I measure it in L/100km, not what the guage tells me! I'll try cleaning my oxygen sensor the week after next when I have time, and I'll be getting extractors done in a couple of months in the search for better fuel economy.

I've already got a 2.5" exhaust from the cat back and a K&N panel filter . . . will probably go for a ridiculously expensive SS Inductions CAI - with petrol prices the way they are I figure all this will pay for itself in another 100 000 km . . .

So yeah if anyone has any advice on what to check in terms of my engine, that'd be really helpful.

Cheers
Sam

[mouce]

VS Supercharged V6 CAI costs about $50 from Holden. Hell of a lot cheaper than the SS inductions one. Just thought you should know.