Citroen high fuel consumption

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Citroen high fuel consumption

Postby Greg.H » Fri Mar 22, 2013 10:47 pm

Hi folks

2003 Citroen Berlingo 1.4 petrol came to me with high fuel consumption issue.( 25MPG on long run)

It had high HC and CO.Smoked it but was not found vacuum leak and decided to do ultrasonic clean on injectors.CO and HC gone down a bit as a result
Checked live data with scanner and scoped it with Pico.all looks fine except one thing what i couldn't get my head around.
Looking at live data lambda sensor wave reach 820mV and goes back to 48mV so that is good but i noticed when goes lean Close loop change for Open loop.took it for test drive with scanner and stay on Close loop at WOT but with cruise speed at lean value change for Open loop again.Up on borrow my friend scanner same thing happen with that too.

I came across with a strange thing on french cars and this is another nice one
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Re: Citroen high fuel consumption

Postby arjen » Fri Mar 22, 2013 11:03 pm

Do you have any dtc's?
You can take a look at the fuel trims to see how much and in wich way the adaption is out of range.
What's the frequentie from the lambda signal and is the signal high time the same as the signal low time?
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Re: Citroen high fuel consumption

Postby Greg.H » Fri Mar 22, 2013 11:52 pm

Hi

there is no DTC.Fuel trim around 5 in positive adaption.waves once/second as it should and signal stay same time in high than in low.
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Re: Citroen high fuel consumption

Postby arjen » Sat Mar 23, 2013 9:21 am

What are the values from the 4 gas test?

I think the scanner is not correct. Most scanners have a function to give information from the lambda sensor in text, this value changes constantly from rich to lean. I think you see these values but the scanner puts them onder the open/closed loop function.

When the engine is running fine, lambda is correct en fuel trims are normal, then you might have a cat problem.
Normally this should give a dtc, but sometimes there is a 'dummy' placed for the second lambda.
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Re: Citroen high fuel consumption

Postby Greg.H » Mon Mar 25, 2013 10:59 pm

Hi

At 1500 rpm after injectors cleaning:
CO:0.00
HC:9
Lambda:1.00
O2:0.11

I looked lambda in graph mode and was switching fine.
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Re: Citroen high fuel consumption

Postby arjen » Tue Mar 26, 2013 7:04 am

Looks like everything is okay after you cleaned the injectors. The only problem is your scanner confusing you :)
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Re: Citroen high fuel consumption

Postby Greg.H » Tue Mar 26, 2013 9:08 pm

This is my problem too.Has to be something what calls high fuel consumption but everything looks fine.should do more than 25MPG on long run.The owner good friend of mine and i know with his driving style that is very poor figure.
i checked it with 3 scanner now and all of them goes from close to open loop at low lambda voltage
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