MAF showing 0% airflow

Well, my new Bosch MAF arrived and i fitted it to the zed expecting this problem to be resolved. Sadly for me the live data is exactly the same :( 0.00% air flow.

So i don't really know what to do now :idunno:

Could it be an ECU problem? Apart from a slightly uneven idle the zed drives perfect, well to me anyway.

Although it could be driving terribly, without a 2.0 zed nearby to compare with i wouldn't know. if i can sort this out i will post back with a conclusion.

Thanks All, tug :thumbsup:
 
Can you return the MAF? Bmw usually pretty good with that kind of thing as long as you haven’t destroyed the packaging. Have you tried a Valvetronic adaptations reset (assuming you have INPA)?

Just so I’m absolutely clear, have you ever seen a live stream for airflow on a comparable car using exactly the same software?
 
ph001 said:
Can you return the MAF? Bmw usually pretty good with that kind of thing as long as you haven’t destroyed the packaging. Have you tried a Valvetronic adaptations reset (assuming you have INPA)?

Just so I’m absolutely clear, have you ever seen a live stream for airflow on a comparable car using exactly the same software?
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is my 3.0i comparable enough ? i did that 5 mins ago for you, just for you. :thumbsup:
 

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All I’ve been saying all along here is that you have to be careful concluding a fault with the AFM here as not all software (and specifically INPA) report airflow data where you would expect.

Now if you are saying you have tried the same software on the same model car and one shows data whilst the other does not then I would agree that sounds odd. Is that what you are saying?
 
what i am saying is multifold, not all software shows everything, as i say inpa does not it seem show flow, but many software does but they conversely do not have the tuning abilities of inpa.
When it comes to the problem that Tug is having it seems more complex. He has now got 3 maf's one brand new bosch i believe, none show a reading on my equipment, he has had it looked at and he tell me he has a live 12v feed , a live 5v feed and 2 other earths which i must assume also work but this is 2nd hand info, i am of the opinion that one of the earth connections goes to the return of the 12v and assume the other goes cpu - i dont know as i didnt test it personally, his tester informed him it was dead - i doubt that now but the question remains of why no reading is unanswered. perhaps we could get a few members to check theirs and let us now.
i used "obd harry" free on android with a cheap obd2 5 quid jobbie. the test was done on the wifes diesel passat, Tugs 2.0 e85 and my 3.0i e85, only tug had no maf readings.
I have also done a little research and found other cars have been known to have a zero reading for Maf, also with lumpy tickover unsurprisingly. I have also found that 3 series have 2 relays and fuses for the maf, but so far i have yet to find one on a zed but as a 3 .0i is used in the e46 its a possibility i think..

its also interesting that my motorhome had a eml light on for almost 2 years with absolutely no effect whatsoever, and when i tested it i got a fault code showing an air temp error, i had a few people try to to solve it,and that had 2 mafs fitted to no effect.. However, although it had no running symptoms (30 mpg from a 3840k vehicle) or issues the mot law changed and i had to find the problem. After the professionals had had a go and failed with the mot impending.. It turned out there is a fuse for the maf on some vehicles as i said and now know.
 
I guess where all the uncertainty lies is that all the ecu’s here are completely different. We know INPA doesn’t show AFM output where you would expect it to. I bet this has caught out a lot of people in the past needlessly buying new AFM’s. It’s difficult to make any further conclusions until you try your software on a 2.0l Z4.
 
Mafs are certainly 1 of the most curious things sometimes. They can change things u wouldn't even think of. Had to replace mine recently purely because the revs starting rising whenever the brake pedal was pressed. Realised it only happened at the point the brake lights came on. Also got a friend with an Audi quattro that refused to run in 4wd because of a faulty maf. My live data also read zero. Upon changing the MAF the live data went back to being variable in tune with the engines throttle position. My car drove perfectly and idled perfectly until I braked. I would suggest changing it. If in doubt just purchase a working/tested used 1 first.
 
ph001 said:
I guess where all the uncertainty lies is that all the ecu’s here are completely different. We know INPA doesn’t show AFM output where you would expect it to. I bet this has caught out a lot of people in the past needlessly buying new AFM’s. It’s difficult to make any further conclusions until you try your software on a 2.0l Z4.
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im assuming you mean another 2.0 ?
 
This is getting really interesting, the MAF technology is, in my mind, very confusing for such a simple design. You lads really know your stuff and RW has surprised me with his in depth knowledge of this (pity he wasn't as good at playing pool :lol: )

Yes, i would love to try a known working MAF on mine which would simplify everything. Perhaps i could borrow somebody's at ZEDFEST if they would be so kind.

However, yesterday after fitting the new MAF on mine the car feels more settled, smoother and idles a little better although not perfect. I thought, perhaps the placebo effect but it deffo feels better :?

On my cheapo OBD2 reader 1 of the categories in the live stream is "Air Status" and this is OFF! could this mean that somebody in the past before my ownership could have p!ssed about with the ECU? I dont know as much as you guys, it could just mean nothing.

Or, again i have yet another DUFF MAF :idunno: Again it would sort the problem if i could borrow a known working MAF.

Thanks again all for the help. tug :thumbsup:
 
I did mate, the same part number as the original. Any thoughts on "AIR STATUS- OFF" on me reader?
 
tug said:
I did mate, the same part number as the original. Any thoughts on "AIR STATUS- OFF" on me reader?
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Wait.. Did you check and order the right part or did you copy the the number from the maf you have , as that might be duplicating the error if it was wrong in the first place :thumbsup:
 
I just bought the one that said was correct for my motor which is the same as the original. Do you think if i ordered a different one ie. "HELLA" for instance it might solve it mate?
 
tug said:
I just bought the one that said was correct for my motor which is the same as the original. Do you think if i ordered a different one ie. "HELLA" for instance it might solve it mate?
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no not hella Bosch is defacto
 
Glad ya said that mate, Hella MAF's are £150 odd for my motor FFS :o

Oh, after fitting the new MAF when plugging the reader in it initially gives an airflow reading then after a second it goes to 0.00% does this mean anything?
 
tug said:
I did mate, the same part number as the original. Any thoughts on "AIR STATUS- OFF" on me reader?
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I'm shooting from the hip here but I'd say that multiple replacement MAF has probably excluded that as a cause. I'm wondering whether "AIR STATUS- OFF" and zero readings simply mean your software isn't reading and nothing has ever been wrong with your MAF.

Lots of members with the N46 2.0 have suffered from rough idle unconnected to MAF and can be caused by a range of factors from a valvetronic motor, to leaky intake, the infamous 2.0 manifold, o2 sensors, plugs, coil packs or even a bad fuel cap or oil cap seal. If it's a little bit 'fluffy' when gently blipping the revs to just above idle I'd be asking questions about the valvetronic motor and eliminating that first. I'm guessing (and I am guessing) that it can be tested on the car and as with all things BMW they don't always throw codes.
 
Thanks mate, all the things you point to have been sorted over time, it has had a new valvetronic fitted after the original failed and the manifold has been TIG welded. And leaks have been rectified as and when needed, although it has a small water leak on the front union pipe coming from the radiator which will be replaced shortly.

The car itself runs fine and no problems apart from a slight uneven idle which as you say is an accepted definition of the N46 2.0i. The airflow readings have been tested on several different scanners now & all read the same 0.00%. Still unsure of the "Air Status - Off" don't know what that means :idunno:

Would having the valvetronic adaptations cleared help do you think?

Thanks mate, tug :thumbsup:
 
I don’t think there is anything you can do to the ecu in terms of coding to make it ignore the MAF, so somebody messing with it sounds extremely unlikely. Similarly, the odds of your brand new MAF being faulty (as well as all the others you have tried) is probably about a billion to one.

Definitely try the Valvetronic adaptations reset.
 
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