liters per 100k's

Holden/Delco Tuning. ALDL, OBD 1.5. Circa 1989 to 2004.
drippy
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Vy V6

liters per 100k's

Post by drippy »

hey all im just wondering how i can update the liters per 100 in my vy, i know its way off, is is something that needs to be changed via tech 2 or is there something in the tune i can tweak to fix it? it always says im doing 5-6liters per 100 lol when im really doing 11-12, ive just been halving the K's till empty and everything but id like to fix it haha

any solutions would be fantastic
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VL400
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Re: liters per 100k's

Post by VL400 »

What has changed on the vehicle for it to be wrong?
sdh
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Re: liters per 100k's

Post by sdh »

Sounds like there must be something else going on.
If you start in engineering mode and look at the fuel tank liters, is the number correct? Presumably if the gauge is reading correct then number should be ok.
Does anyone know how the fuel consumption is calculated? It can't be calculated on fuel tank volume over time because it wouldn't update quick enough and would be wrong during cornering.
Is there a fuel pressure sensor? They could use that and calculate the fuel consumption based on injector pulses. So maybe the sensor is faulty?
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Holden202T
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Re: liters per 100k's

Post by Holden202T »

i'm pretty sure there is a calc which uses injector opening times v's distance travelled to work out how much it going through the motor for given km's.
yoda69
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Re: liters per 100k's

Post by yoda69 »

For VT and later there is information over ALDL from the ECU that is used by the instruments with the odometer to calculate consumption. I'm not sure, but believe VR/vs used the same settings. When you disable chatter while logging the vehicle sees no fuel usage.

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antus
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Re: liters per 100k's

Post by antus »

It sounds to me like its had massive injectors installed and not had the injector flow rate updated appropriately. I would not be suprised if the mixtures are as far out as the fuel consumption guage is.
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drippy
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cars: Vk V6
Vy V6

Re: liters per 100k's

Post by drippy »

ive installed 32lb injectors and updated the the base flow rate accordingly, car runs fine with the tune atm

but it shows im using 6l per 100 which i i know i am not getting that good of economy

is there any other table i can adjust in the vy $060A xdf to get it back to actual usage ect? or is the table not defined?

edit: i should add ive got a raptor kit on it as well, ever since i started tuning it, it has not read correctly but the car runs fine and has been running fine for about 12 months now. runs a little rich but i haven't had the time to fine tune it


on a second note, has someone made a copy paste style excel sheet for getting mixers and spark bang on target? without having to go through the logs manually?
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Re: liters per 100k's

Post by yoda69 »

Try the 2 Bytes at address $578A/B, should be $03EA.
Given you've changed Injector rate from about 22 to 32lb, this is ~45% increase try changing to $05AC.
If you actually work out the percentage difference of the standard injectors compared to your new ones you should be able to get it closer (1+(New-Old)/Old) x $03EA
Note, as per previous post, if your logging while drivimg the Trip Computer will not see any fuel use and show lower than expected numbers.

Also do the same with the values in $578C/D, should be $5069, try increasing by 45% as well.

EDIT: just make sure you update both by the same percentage, pretty sure one does fuel used and the other litres/hour.

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drippy
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Re: liters per 100k's

Post by drippy »

ill give it a try, only ive never edited any of this in hex

is there an editor in TP or do i have to use another program?
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VL400
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Re: liters per 100k's

Post by VL400 »

There is a hex editor in TP :thumbup: Under the Tools menu and then Advanced.
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