MAF showing 0% airflow

[ph001]

If your inpa is reporting no reading then your equipment is faulty or your cars are. I foresee a wonderful afternoons entertainment at zedfest where you attempt to prove there is no through flow of air going past a moving engine air intake.
And to clarify, I am NOT Saying he needs a new Maf. I am saying there is no reading from the maf., an entirely different proposition.
Before this becomes handbags at dawn, may I suggest you try something else other than inpa to take live data from ?
There is no avoiding the simple fact that air MUST be passing past the maf into the engine or it could not function.

Show me a screenshot of your car displaying a value for "HFM sensor air mass" and your argument may have some weight to it.

Of course nobody is denying that there is airflow through the AFM...obviously there is, it's just that the ECU does not report it to INPA as HFM sensor air mass (on the 2.5Si and 3.0Si engines at least). At the risk of repeating myself, it's probably displayed in the MESSWERTBLOCK1 screen as "luftmasse".

[road warrior]

https://youtu.be/7gw_Uz4OdoE

try something aside from inpa, using it alone it seems to limit your information, please remember im just trying to help fix my friend's car, now if you were prepared to lend your vast experience in a hands on capacity like i am,

[tug]

Well, i am gonna report another finding in the elusive airflow in my MAF. This afternoon after wok i connected my portable OBD2 reader in & drove spiritedly home about 18 miles, and again 0.00 on the live stream

So payed a visit to Loughborough BMW specialist indie. Graham, the head tech (top bloke) came straight out (we are old friends which helps ) and tested the MAF connector plug to see if there was a problem there, and happy t' say working perfectly.

So it seems the MAF sensor is (in his words) "dead as a nuns sex life"

So, have ordered a new MAF. I will post back if this resolves the problem for me or not

Thanks for the help everyone. Cheers, tug

[road warrior]

I would call that a result

[tug]

I would call that a result

Would probably never have known bout it if it wernt for yo me old mucker.

[road warrior]

I would call that a result

Would probably never have known bout it if it wernt for yo me old mucker.

lets hope eh

[tug]

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

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

[ph001]

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?

[road warrior]

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?

is my 3.0i comparable enough ? i did that 5 mins ago for you, just for you.

[ph001]

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?

[road warrior]

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.

[ph001]

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.

[Timmo478]

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.

[road warrior]

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.

im assuming you mean another 2.0 ?

[tug]

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 )

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 Again it would sort the problem if i could borrow a known working MAF.

Thanks again all for the help. tug