onboard computer showing weird fuel use.

[|sAs|]

Hi guys, Hope you can help me.
The car is a 2001 ph1 clio sport.
The car runs fine, no misfiring or anything like that.
But when driving, the trip computer shows that the car is using way to much fuel.

When rolling at 60mph, no gear selected, it Will show max fuel used 29,9L/ 100km
When flooring it, it Will show smaller and smaller figures.

I Will do a video later today or tomorrow to show more exactly.

 

[|sAs|]

http://www.youtube.com/watch?v=fOIRNIrtULw

 

[Goodj]

you'll get better results if you leave the car in gear when coasting.

 

[dazzyb87]

if by no gear selected u mean its out of gear then it will show that it is using alot of fuel. while moving you should keep it in gear. keeping it simple, the turning of the wheels goes through the gear box and keeps the engine turning (the simple explanation) even when u dont depress the accelerator. but taking it out of gear the engine needs to inject more fuel to keep it turning.

 

[|sAs|]

Its showing 3 km pr l. Thats alot, thats 3 times more then when doing 60 mph normally. 9mpg its says when translateted
But there is no difference in gear or not.

I dont think its the water temp sensor, since it unlocks to 7200 rpm when hot.
I dont think its the co2 (lambda) sensor, since the car is running fine.

 

[|sAs|]

And thanks for the tips, I have had a clio sport for more then 5 years.
I am familiar with the car, but this is unusual.
Its like the car trip computer is... Fucked up
9mpg is.. Good for a veyron, not for my clio.

 

[|sAs|]

Does anyone know how the car gets the mpg figure ?

 

[aucky]

I think it takes it off the speed somehow.

My Grandad's ph1 has a faulty speed sensor which causes the dial to drop off completely. When this happens the trip computer mpg plummets because the car thinks it is using fuel but not moving. 0mpg.

 

[|sAs|]

Thanks aucky, but the speedo is working.

 

[mr.pink87]

I think the computer gets a signal from the engine ECU (some kind of injector duty signal) and calculates the mpg.

 

[fletch8]

is it actually using more fuel

 

[|sAs|]

Im not sure of its using more fuel.
Today i took a drive, and i can see that the mpg is only related to the speed, the faster the less fuel used, does not matter if im in 3rd or 5th gear, and that makes me think that the throttle position sensor or flywheel sensor is making this problem.. ?

 

[fletch8]

if my car was using 9mpg id most certainly notice,

 

[|sAs|]

Mrpink87> I was thinking its something like that, but if the ecu is missing information from a sensor, it cannot send the real figure

 

[mr.pink87]

Maybe the ECU is sending a faulty information or there is a problem with the wiring!?

 

[edde]

Check the fuel level wires. The ECU tries to be intelegent when it doesn't know fuel flow rates etc and guess for a bit before giving up guessing your MPG.