Technical Fuel Consumption Checklist

[nomatter]

No problem.
So, sorry to ask again, but is this what you are suggesting to do: fill the tank, drive, say 200km, then refill the tank so it's full and do the calculations based on the amount of fuel i have added?

I have tried putting 20 litres too (1/2 tank); i was able to drive only 230-250km (by my measuring method). This corresponds to 27-30MPG.
Unless the meter that counts travelled kilometers is wrong, I don't think that my measuring is that inaccurate; I have actually done the measuring for no less than 10 times with similar results.

I'd like to check the above mentioned responsible units: ECU, lambda, etc., but I don't have instructions about how to proceed; Can anybody provide these instructions please?

 

[rallycinq]

So, sorry to ask again, but is this what you are suggesting to do: fill the tank, drive, say 200km, then refill the tank so it's full and do the calculations based on the amount of fuel i have added?

Yup, thats the most accurate way.

On your other question, take your spark plugs out. Look at the nose of the plugs, they should be light brown, sort of colour of sand.

If they are dark to black, your engine is running rich, using too much fuel.

However, if your management system is adding too much fuel, then the lambda would pick it up and put the management light on.

Cheers

D

 

[nomatter]

However, if your management system is adding too much fuel, then the lambda would pick it up and put the management light on.

OK. I'll check the plugs and try to figure out if lambda is responsible for anything.

Someone said I should also check the temperature sensor; is it related to the temperature gauge at all, or is it an independent unit? I mean, if the engine temperature readings are fine, should I consider this sensor to be working well?

Thanks.

 

[arc]

check the handbrake isnt dragging as well, that can impact mpg

there are two coolant temperature sensors. one for the gauge on the back of the head, near no1 cylinder.

the one for the ECU is in the inlet manifold, it sticks out the side and has a blue plug on it.

If the ECU sensor is faulty, it can mess up the fueling. The gauge sensor is purely for the gauge, and not going to effect fueling.

 

[arc]

you've posted that 3 times now, and i answered the temp sensor bit for ya up there ^^

 

[nomatter]

Yeah i know. The reason is, that I had to refresh the site 3 times, resulting in those posts.

I found your post only after i posted the question
Sorry and thanks for advices.

 

[rallycinq]

Most engine related problems with overfuelling would be picked up by the lambda and either adjusted for by the ecu, or would through the code light on.

I would follow the suggestion above about external forces, like brakes dragging.

Cheers

D