O2 Sensor? Tune?

[syfon]

Hey guys,

First of all, I'm not sure if it is my O2 sensor that may be cuasing this problem, so any advice would be great

Last Thursday evening I filled my car up with BP 98 right to the top and have since been driving my Skyline on a daily basis. At the moment I have just under 1/4 of a tank of petrol left and have travelled about 315km's. I am not very happy with the fuel economy my car has been getting. Yes I know, fuel economy has been discussed many times before but I would like to know what can possibly cause sh!tty fuel economy when I have been driving pretty softly.

Yes I have been giving my car the occasional squirt but 90% of the time its just been off-boost driving. Does anybody know the exact capacity of the fuel tank in the Series 2 R33 GTS25-t?

My car has the usual modifications - turbo-back exhaust, FMIC, air-pod, electronic boost controller. However, since I have owned the car, I have not had it tuned. I am planning to install a HKS fuel-cut defender and then have my car tuned soon.

I am just after some reasons as to why I am getting poor fuel economy? Could it be that my O2 sensor is stuffed? The car needs a tune?

Cheers for any help guys

[Niksmo]

stock 33's run rich dude, i sugest upgrading your fuel pump before u get it tuned too.

[Dani Boi]

It says on all websites that the fuel tank capacity is 65L, but I've never been able to fill up over 51L running the needle slightly below E. If your planning on buying a computer or piggyback, buy that first before you get it tuned, that way it will save you having to re-tune it in the future. Your not labouring the engine are you i.e. putting it in 5th at 50km/h or similiar?

[syfon]

I only slot it into 5th if im over 70km/h or so.

There is a bosch 040 fuel pump for sale in the FS section....how hard are they to install? and once installed and tuned whats the rough power gain?

[SKYRYAN]

You don't gain power from a fuel pump.

You buy a fuel pump if you need more fuel to the engine (ie. bigger turbo)

Or your stock pump is on it's way out, which after 10-16 years I'm betting it is getting a bit worn. A dyno run to check AFR's and checking the pressure in the fuel line will help determine that.

PS. You can't re-tune the stock ECU.

Edited July 1, 2009 by SKYRYAN

[syfon]

Yeah i know you can't re-tune the stock ECU....i would need a piggy back or to get it chipped or something.

Would it be worth installing a fuel-cu defender and then getting the boost controller tuned?

[Dani Boi]

No. Service the car if you haven't in a while (Oil & Filter, perhaps air/fuel filter and spark plugs). Then if your still getting poor fuel economy then get yourself an ECU or piggyback then get it tuned, scrap the fuel cut defender I say...

[Pattygtst]

Check how man litres it takes to fill up and compare to how many kms you did. Pretty simple. Looks ok to me.

[syfon]

How much does a piggy back ecu set you back? As for the fuel-cut defender, my brother brought it and never used it so i can stick it in my car for free if i want lol

It has been around 7500kms since i changed the plugs and 4000kms since last oil/filter change.

Im going to change the plugs/oil filter/oil/air filter etc this weekend

What oil do you guys use? I'm using shell 5w-40, and my cars runs perfect on it:)

[Pattygtst]

when i put my power fc in i didnt notice any better fuel economy. The power was about the same too, the only thing that changed was the delivery of power.

I was getting about 400kms to 45 litres at best. as mentioned above check plugs, fuel & oil filter, 02 sensor.

[SKYRYAN]

Clean your AFM with some electrical contact cleaner too. I bought some the other day, was $38 for a large can

[syfon]

Well im almost on empty now, so i'll fill her up on the way home from work and i'll keep putting about in her, then on the weekend ill service her and let you know how she goes

[Ehgriez]

id say from the fuel light youd be looking at 56L or say to fill up ? Yes/No?

So with a quarter left thats say 38L

38/3.18 = 11.94L/100km

About normal.

[Travo]

Give it an air leak test.

I had a few bad air leaks around the fmic.

I was getting 320km - 350km to a tank just putting around with the odd boot.

After fixing these leaks I get about 400km to a tank and obviously it drives alot better too.

[bubba]

Nothing really abnormal about that fuel consumption, I don't know about anyone else but I didn't buy a skyline or a Stagea for their economy!

[syfon]

Haha i didn't buy a skyline for the fuel economy either! If i wanted fuel economy i would have brought a corolla

[bubba]

Exactly! but at 315km from 3/4 tank that's really not that bad as far as skylines go.

My 32 tuned rich as struggled to get 300km to a 55L tank, lots of highway driving would see about 400km.

I think the Stag has a 65L tank and that gets about 400km/tank around town (hiflow turbo, 1.8T etc) and on the long trips down south I've managed to stretch it out to nearly 600km/tank.

Edited July 1, 2009 by bubba

[Dorigecko]

What oil are you using?

I run a 10w in my 25det and i'll get a good 450km out of it easily. but 80% of the driving i do is to perth and back. run pretty much same shit you do except i have had a tune on a piggyback SAFC-II.

Test your AFM. lambda works with that to determine your Air-fuel mix.

Oh, are you running a "de-cat" pipe? if you are, that'll be screwing with your oxygen sensor readings. backpressure = accuracy. like a lotto ball. can never count it until it stops for juuuust a second.

[Davyboy]

Hey guys,

First of all, I'm not sure if it is my O2 sensor that may be cuasing this problem, so any advice would be great

Last Thursday evening I filled my car up with BP 98 right to the top and have since been driving my Skyline on a daily basis. At the moment I have just under 1/4 of a tank of petrol left and have travelled about 315km's. I am not very happy with the fuel economy my car has been getting. Yes I know, fuel economy has been discussed many times before but I would like to know what can possibly cause sh!tty fuel economy when I have been driving pretty softly.

Yes I have been giving my car the occasional squirt but 90% of the time its just been off-boost driving. Does anybody know the exact capacity of the fuel tank in the Series 2 R33 GTS25-t?

My car has the usual modifications - turbo-back exhaust, FMIC, air-pod, electronic boost controller. However, since I have owned the car, I have not had it tuned. I am planning to install a HKS fuel-cut defender and then have my car tuned soon.

I am just after some reasons as to why I am getting poor fuel economy? Could it be that my O2 sensor is stuffed? The car needs a tune?

Cheers for any help guys

mate id be happy with 315 and 1/4 left

I have a series 1.5 R33 GTS-T with exactly the same mods as u, (Except splitfire coil packs) and i only get about 320 to a full tank city driving. Stock computers run mega rich man, and even more so when u boost them coz the stock computer is un-tuneable.

An full standalone would be the way to go, because then you can get all your parameters changed depending on if u want power or economy, or a balance of both.

[syfon]

Do you guys reckon it is worth getting an SAFC-II for my car and then getting it tuned properly? So that way i can adjust my fuel settings etc.

Also, I am running a catalytic converter, however once i pass pits the de-cat goes back in, I like my flames