fuel!!

[Andrew_sup]

hey guys i got a fueling problem, which is im using way to much fuel i can do a journey of 14 miles and it will cost a £5 which is nutts even for a 3.0ltr and its only a n/a auto. can notice a slight smell of petrol when i get out after a good blast and it idles at about 500-600 rpm. will a simple service cure this? and what mpg should i expect.

[Al Massey]

it depends if you use your overdrive feature to get into 4th gear,i get 350 - 400 in my manual on motorways but bout 300ish town driving,have a look at your plugs and air filter to see what condition there in

[ChrisSZ]

Check your 02 sensors - you might wanna take them out and soak them in lemon juice overnight to clean them. This could make a helluva difference. Also, plugs etc. as mentioned above.

[miko_supra]

check that the o2 sensors are plugged in too! mate was getting bad fueling on his. turns out the previous owner had left one of em unplugged

[Andrew_sup]

thanks guys i'll give it a once over tomorrow needs a service too only had it a few weeks. how much do the o2 sensors retail for if they need replacing or will the lemon juice do the job

[Soop Dogg]

There's an FAQ on how to check your O2 sensors.

 

Click HERE.

 

I'd like to add to what they say there though.

 

If you're not getting the readings mentioned or want to confirm the operation of the O2 sensors, rev the engine taking it up to over 2k revs sharply and then let the throttle off quickly whilst looking at the voltmeter. As the ECU adjusts the fuelling for the sudden changes in load you should see the voltage vary up and down between 0v and close to 1v. If this doesn't happen, you'll probably see only a few millivolts or nothing at all. In this case, the sensor is probably knackered and the ECU isn't getting any signals from it.

 

When the ECU receives low voltage (tending towards zero) from the O2 sensor, it interprets this as running lean and will try to add more fuel. In the case of a knackered O2 sensor, it will keep adding fuel, waiting for the voltage returned from the sensor to climb. When it doesn't climb to a normal level, the ECU never backs off the fuelling and the car runs very rich.

 

Hope this helps. Let us know how you get on.

[supraman382]

Felt mine was a little thirsty recently also but just had an MOT and the emission tests were spot on. Lambda was 1.00 (Min 0.97 - Max 1.03) despite this could the sensor still need a clean or replacing or would there have been an issue with emmisions?

 

Cheers

[Suprasteve]

sounds like the sensor is ok.

 

normally give a high reading if dodgy

[Rory]

Mine smells a little of petrol when I get out too , the consumption seems normal though.