Fuel Consumption Issue

[dom123]

hey all,

my consumption has been playing up alot recently . Iv put in a CAI kit from autobahn(well known drift one) whilst this problem was occuring and its still happening.

what happens is the consumption reads crazy figures like 40 or so then will gradually drop to around 15 after a while of driving.

I have also bipassed the breather i dont no if this is causing the issue maybe the hose i used was too thin or something???

anyways any help would be much appreciated!

cheers
dom

[Golf Loon]

Is it using heaps of fuel? more than normal??

MAF or temp sensor I reckon.

[MattyT]

My MFA has always read massive numbers in the first few minutes of driving and eventually settled down to somewhere around 9 after a few minutes. Sounds like normal operation to me.

[dom123]

but the maf was replaced just before i bought it. the consumption seems pretty normal just the reading is whacked out

[Soundofav6]

I have always had same problem. We are in the Veyron territory in the first few mins. I have always suspect it to be either MAF and or O2 senor, my record was stuck in jammed packed car park for 15 mins 90+L /100, drop back to "normal" 11L/100 on the road.

Every time I had enough money to deal with this issue something always comes up. I do believe it is one of those senors.

Over the weekend I was driving through the City with heavy traffic 35L/100. Last tank I tried using injector clearner, and it seems to be better. Perhaps give it a go.

[Mrk_Mickey]

Dom, I get the same thing too mate. Unless you're using a noticeably larger amount of fuel, I don't think you've got anything to worry about.

EDIT: Actually, I'm replacing my spark plugs now because my car isn't running too good, and is using more fuel. Maybe you should look at your spark plugs?

P.S You gotta show me your CAI when I see you next cos I've wanted one for a while now and I was gonna get that one!

[dom123]

lol my plugs are brand spankers! i just took a look and it looks like when i bypassed the breather the hose was too stiff and its not fixed properly so its letting in air so im guessing this may very well be the issue so i need new lil bit of hose.

mickey come look at it man its pretty easily done and sounds nice!

[Mrk_Mickey]

Which breather are you talking about exactly?

[sydVR6]

You will notice the car using more fuel if you've recently fitted a CAI - that's simply how the MAF metre is designed. The more oxygen that passes the MAF, the more fuel the injection system adjusts into the mixture. Aftermarket chips compensate for this type of thing.

15l/100km sounds within normal parametres for an urban running VR6.
New plugs, etc, will help. Check your tyre pressures too - anything less than about 36psi is just creating drag - just my 2c.

[MattyT]

The other thing to consider is that I suspect that the MAF computer calculates L/hr based on distance travelled vs fuel actually used. Hence when u first start up you are eating fuel but going nowhere. Same thing for why the numbers start to become reasonable after you have travelled a few kilometers.

Let it be said that I never have my MAF/MFA/whatever showing L/hr - its on oil temp ;D

[Shteifen]

i dont reckon this is a problem at all. if your overall fuel economy is crap and u actually are using heaps of fuel then ya thats a problem
But if ur just worried that just MFA says ur using 99.9L/100km for the first few minutes, take into consideration that it is a reading of litres per hundred kms yeah? so if u just started ur car and let it idle for a minute or so, or even hardly at all while you turned the lights on, and got ur seat belt on (buckle up!), then drove 3 meters down the road and wonder why ur reading says uve use heaps of fuel for the distance uve travelled well.....its cos you have. you've only moved 3 meters and ur car is generally going to use heaps of fuel to warm up and u havent moved car so there for the reading is high.

try it next time. and ull notice if ur car is a little warm the number will reduce alot quicker than from a dead cold start. makes sense no?

-steve

[The_Hawk]

When I fill up I reset that meter and it's always fun to see what it goes up to. If I hit 1st hard out of the driveway it can go up to 99L/100km, but then it drops very quickly, even staying on it round the first few corners rarely see's it stay above 30L/100KM. Bt the time I have driven the 5KM home from the servo I'm usually back under 12.

According to the manual for a manual car you get:
Manual is here if you want a copy: http://www.mooshen.com/vwwc/golf/

90km/h - 7.3l/100KM
120km/h - 8.9l/100KM
"Urban" - 12.5l/100KM

and for the Auto:

90km/h - 7.7l/100KM
120km/h - 9.4l/100KM
"Urban" - 13.8l/100KM

In all my testing these numbers come out near spot on in my car and I have the DRIFT CAI and a high flow exhaust.

Cruising in 80 zones I can see figures under 8L, on a run to Melbourne I was averaging about 8.5L, driving to and from the train station every day (which is barely enough time for the car to warm up) I can get an average of near 14l/100KM, but this really is the extreme since it's all very short runs.

I keep logs of all my fuel use and can tell you in the last two year my running average is sitting at 11.1L/100KM which is MOSTLY trips to the station.


Long story short, I don't know how people get (and maintain) figures that are that much higher?

[MattyT]

Neither really. Must be leadfooting it hardcore.

[Povi]

haha honestly tell me its not tempting in a VR though...