R33 Bad Fuel Economy

[rich flavour]

thanks paul i was thinking im wasting this fuel i may aswell be making more power also do you think my r34 gtr fuel pump isnt helping or it should make a diff??

Edited March 16, 2008 by rich flavour

[Adriano]

I wouldnt be warming up a new built motor by letting it ilde for 10 mins, its a recipe for glazing up the bores.

[paulr33]

34R pump is ok, as the others have said 10minu idle is doing more harm than good

30sec at the most when cold is plently, the engine needs to be at operating temp, not cold

[WET-25T]

What the hell, how do you guys get so mans k's out of a tank.

I only have a r34 gtt side mount, full exhaust, pod filter and am using the high boost DIY and i get 250 to 300 km's out of a tank with 98 octane fuel. I tend to flog it abit but still.

I got 300 km;s when i tried not to flog it so much and thats the best i could get.

[75coupe]

ah you want to know the secret to getting more Ks from a tank eh?.... I dunno guys should we tell him...

[rich flavour]

lol what is it

[krzysiu]

75coupe is just talking crap There is no secret

[TiTAN]

Its called driving off boost. That combined with a piggy back/aftermarket ECU where the load points up to 3000-3500 are leaned out a bit and its easy to get 400-500km from a tank, then the money you save on fuel pays for the upgrade.

[75coupe]

75coupe is just talking crap There is no secret

oh dude, I could of them goin for days on that one...

[eddieeeee-ro]

i was getting about 250kms a tank with similar mods...

got a powerfc installed and tuned = more power and 400-450 a tank

[rich flavour]

oh dude, I could of them goin for days on that one...

hahahahahhah nice try but looking for help and there are plenty giving it so pipe down over there

[rich flavour]

i was getting about 250kms a tank with similar mods...

got a powerfc installed and tuned = more power and 400-450 a tank

cheers mate was your ecu chipped or standed?

Edited March 16, 2008 by rich flavour

[Kaido_RR]

hi michael

whilst i usually avoid cross forum member attacks etc but anyway - given his list of mods and typical fuel economy most GTST guys see

i still think that its his ECU at fault, no where its a case of it just needs a decent tune, a sensor is toast, someone's remapped it to homo settings, or he has a non-supported 02 snsor etc

it could be many many things, but overall one of the essential fucntions of the ECU is fuel injection control and part of that is 02 feedback, which in turn gives you decent fuel economy 300kms+ to a tank.

short of wierd things such as split fuel hoses, loose fuel pumps, wierd filling up tank procedures (ie: him saying a full tank is really 30 liters instead of 50) then i suspect the ECU and tune is the next likely culprit. the recommended action would be to remap it, piggyback it, or change the ecu. if he isnt prepared to do then its needs more debuggin work on the dyno and on the street with a wideband sensor, which just wastes time and $. and besides he will make more power & response with either a remap, piggyback or standalone anyway

hey paul,

sorry if it came across as a member attack that wasn't my intention your 1st post was vague so i didn't think much from it.

from my experience with 3 skylines with similar mods they are able to get 400-500km out of tank with a problem, so leads me to think that is something other than the ecu ...

you mention putting that on a dyno, i think that is the best opinion for $40-$50 powerun you will your afr, which can explains alot.

[rich flavour]

ok i put in 20litres thats what the pump said, i got 140k's from driving on boost for about half of it then drove off boost the other and then a bit in between what you think of 140k good or bad??

new ecu

new o2 sensor..

Edited March 17, 2008 by rich flavour

[tridentt150v]

normal

[PM-R33]

Yep sounds about right, driving around town on 98octane, $30 gets you about 19-20litres and just driving off boost with the occasional squirt i normally get about 120-160kms. Out on the highway driving at a constant 100kmh or something fuel economy is obviously very good.

[TTT]

ok i put in 20litres thats what the pump said, i got 140k's from driving on boost for about half of it then drove off boost the other and then a bit in between what you think of 140k good or bad??

new ecu

new o2 sensor..

Just want to confirm your numbers..

How do you know that you got 140km out of 20L?

you filled your car to the brim, then drove for 140km then filled up again and only got 20L?

or

car was bone dry, you put in 20L then when you got to 140km you ran out of juice and parked it?

point I'm making is that by looking at your fuel gauge then odometer to judge isn't acurate.

if you want a true indication, just fill up the tank to the top.

reset the trip counter to 0000

drive around all week or whatever.

Fill up to the top again and make note of litres you put in, and what the trip meter now says.

example.

you filled up, hit reset, drove around for 5 days, did 280km, filled up again and put in 50L on fill up.

that would mean.

50L divided by 280km times 100 = 17.85L per 100km.

50/280*100 = 17.857

your example above would be 20/140*100 = 14.285L per 100km (which is about normal for mixed driving..)

but to get a proper gauge of what it's using, you have to fill up and reset, drive, fill up and calculate properly.

[Guilt-Toy]

When you said changed not long ago, was it changed with a brand new unit ? or a second hand one?

These sensors are only worth 40,000km's.

If its older then that or your unsure how old it is... Change it!

just changed afm few weeks back and oz sensor is also in good nick was also changed not to long ago

[666DAN]

It's amazing how driving style weighs on consumption though...I had a 02 sensor die and my city driving, being more spirited was netting 280kms for 50L. I changed the 02 sensor saw an immediate improvement to 360kms. Now I drive on the highway pretty much the whole time and that figure has blown out to 440kms.

I think that's great for my car considering it's auto and is definately not stock.

[rich flavour]

Just want to confirm your numbers..

How do you know that you got 140km out of 20L?

you filled your car to the brim, then drove for 140km then filled up again and only got 20L?

or

car was bone dry, you put in 20L then when you got to 140km you ran out of juice and parked it?

point I'm making is that by looking at your fuel gauge then odometer to judge isn't acurate.

if you want a true indication, just fill up the tank to the top.

reset the trip counter to 0000

drive around all week or whatever.

Fill up to the top again and make note of litres you put in, and what the trip meter now says.

example.

you filled up, hit reset, drove around for 5 days, did 280km, filled up again and put in 50L on fill up.

that would mean.

50L divided by 280km times 100 = 17.85L per 100km.

50/280*100 = 17.857

your example above would be 20/140*100 = 14.285L per 100km (which is about normal for mixed driving..)

but to get a proper gauge of what it's using, you have to fill up and reset, drive, fill up and calculate properly.

i was driving aorund witht he fuel light on for a a while then was sitting in line at the servo so it was as good as dry as a bone