vs fuel usage

[smith#29]

hey guys, just need some help with my vs commodore exec.

Im averaging around 400km (at the most usually just under) per tank from a full tank of fuel (am i mean full to the top) and thats going easy and mainly high way driving with 30km trips each way (hardly get 350km if driving around town). My sisters car is the same model and all and gets 500km easy.

So i need to know what to do to help with the excessive fuel usage. ive done compression tests, checked spark plugs, air filter, fuel filters, what else should i be looking at? Maybe time to wip the oxygen sensors out and replace? anything else?

 

[88GreenVN]

O2 sensors are a good start. Also the temp sensor for the ECU. Change those and see what you get.

I dropped 1 lt per 100 kms on changing the o2 sensor alone.

 

[chrisdoesitbetter]

a mate of mine was averaging 22L per 100, he changed the o2 sensors and the AFM and now his vs avgs 13.L per 100 so check them out, also try this https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307

 

[smith#29]

ok, thought they would be the go.

with the temp sender, my temp gauge reads within the normal range all the time (same as what all my mates are) so does that mean the temp sender is ok? or is it another one?

Ok, will check the error codes, did that a while ago, and didnt get any errors but ill try it again. i know my airbag light is stayin on too lol.

 

[smith#29]

ok just went and checked my codes again, and got the following: the light flashes once, and then a small pause, then flashes twice with a smaller pause between them. so that means error code 12 yeah? whats this mean if thats right? thats all it gave me.

thanx.

 

[wortus]

There are 2 temperature sensors on the engine. One works the gauge and the other goes to the ECU. When the motor is cold the ECU will run the motor in a differnet mode and it will use more fuel.

 

[VS_Pete]

One is called temperature sensor for the ECU.
The other is called temperature sender to gauge.
Here is a pic the temperature sensor it`s the shiney one and is bigger than the temperature sender which is the one with the black lead on it.

 

[VZ57SSZ]

I have the same problem on my VS, though I think mine is more the 02 sensors as it blows black smoke under accel, what are they worth to change.

 

[88GreenVN]

ok, thought they would be the go.

with the temp sender, my temp gauge reads within the normal range all the time (same as what all my mates are) so does that mean the temp sender is ok? or is it another one?

Ok, will check the error codes, did that a while ago, and didnt get any errors but ill try it again. i know my airbag light is stayin on too lol.

The gauge sensor is working fine in that case. It maybe the ECU sensor that MAY have failed. You should be able to test it with a multi metre to see if it's putting out the correct reading or not. If it is not working at all it will tell the ECU the motor is stone cold and to rich the fuel mix to make it idle smooth.

As the engine warms up the ECU backs off the mix and leans out the motor. If the sensor is dead this fails to happen and your car drinks fuel.

 

[chrisdoesitbetter]

I have the same problem on my VS, though I think mine is more the 02 sensors as it blows black smoke under accel, what are they worth to change.

along with high fuel consumption this is a common o2 sensor fault, as a cheaper alternative unplug your MAF sensor at your airbox, if your engine dies or the revs drop its fine it nothing try replacing that.