strange problem with MAF

hope some one can help, the problem is I have 2002 disco td5 auto pre facelift. it's always been slow of the mark,you have to give plenty of notice pulling off from a rounabout or juction but once it hits around 2000 revs she shoots off, the other day I unplugged the maf sensor which is only 4mths old thinking that it had failed ,the disco would fly off from a juction or roundabout so I thoght it was the maf sensor.so before forking out £84 I thought I should check things first,checked the wiring with a multiemeter , all good checked the input and output voltage all good ,then I plugged in the lynx to check the readings voltage and airflow was all good as well, but if the maf sensor is plugged in it still wont pull away quickly yet unplugged it will ? any ideas please

richie15 said:

I plugged in the lynx to check the readings voltage and airflow was all good as well,

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What were those good readings?...important is the reading when that "around 2000 revs she shoots off" symptom occurs

Is it a genuine one or aftermarket? I had similar issue with my maf, seemed to be ok but the car was not "perfect". Finally i have changed it to a genuine one and the car pulls better even below 2000rpm.

Yes go to Land Rover and buy the maf not Siemens vdo but genuine in a Land Rover box

Thank you all for the replies and let me start by saying Happy New year to you all. Back to my problem the readings were 54 on tick over going up to 560 when I pressed the throttle, I should have recorded the live data at the time but my laptop was low on charge so didn't record at the time. its a britpart sensor fitted so maybe I should buy a genuine unit, Also I thought siemens vdo was the OEM unit.would it be better to borrow another MAF sensor and see if it makes a difference or buy the genuine unit ?

Just unplug it, if you see an improvement in performance then your maf is goosed... the Siemens vdo is not the same as genuine but the same maker (Siemens), only problem is the one from Land Rover costs well over 100 quid

If it went up to 560 just like that without having at least 3000rpm under load that sensor is sh*t though as it cuts out at 2000 rpm as you said i think it's not the case to be under load... when it comes to MAF on Eu3 engines only the genuine LR is 100% reliable, any other make is a lottery, even the OEMs(which are also aftermarkets made by those who are making the genuine ones but at a lower quality)

borrow a known good one(removed from Eu3 engine) and see before you spend big money on genuine LR but you can bin the britpart one and better drive with it unplugged untill you get a good one

richie15 said:

Thank you all for the replies and let me start by saying Happy New year to you all. Back to my problem the readings were 54 on tick over going up to 560 when I pressed the throttle, I should have recorded the live data at the time but my laptop was low on charge so didn't record at the time. its a britpart sensor fitted so maybe I should buy a genuine unit, Also I thought siemens vdo was the OEM unit.would it be better to borrow another MAF sensor and see if it makes a difference or buy the genuine unit ?

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If you can try a genuine one, try and decide after. In my case the aftermarket one (Italian make) showed perfect values on my Nanocom but the engine perfomance was not so nice on low rpms. When I have changed it to a genuine one, also recorded data but could not really see real difference. The only difference was the better engine performance. Magic?

It's not magic but the ''raw'' readings shown by nanocom or other testers would not show the real difference which is revealed only with oscilloscope, i've compared many MAF's (OEM's, cheap ones, branded ones) with genuine LR and the difference in the accuracy of the signal is clearely visible even though the voltages are not far.

thank you all, I will borrow a known good oem quality one and try it.

It seems that it wasnt clear enough that you need genuine LR not OEM or others

richie15 said:

thank you all, I will borrow a known good oem quality one and try it.

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Try genuine one. Maybe you will be "lucky" with the borrowed OEM one which performs well but even if you buy the same it could be slightly different and you will end up having a 100£ new maf and same engine performance.
I have now 2 "good" MAFs on the shelf and one genuine in the car

Thank you berg450 , it must have been my lucky day a friend of a friend had a oem maf spare, tried it working perfect the disco has never run better and even better the chap said I could keep it,hard to believe such a little part can make so much difference.It's like having a new disco now. thank you all for your help,always belived people who drive land rovers or just rovers are a breed apart many thanks. well until some thing else goes wrong,but thats why we love them.