MAF showing 0% airflow

tug

tug

Veteran
 Loughborough
Yesterday we tested my cars system values using Road Warriors software, everything was working in the correct parameters except the MAF, where the reading was "Airflow 0%"

The only niggle my zed has is a lumpy tickover. Other than that she runs perfectly smooth, always starts first time and no fault lights on the dash.

So we disconnected the MAF sensor and i drove her as i normally would :driving: down the motorway for 20 miles home. There was no difference in running and coming to a stop the idle was still lumpy. So it was driving exactly the same as if we hadn't disconnected it.

My question if anyone can help is, what does this mean? Do i need a new MAF? Other than a lumpy idle, the zed runs perfect with no other problems. :idunno:

Thanks for any help/advice you could share. tug :thumbsup:

Oh and we tested RW's other cars and they all read normal airflow :(
 
With the MAF not working the car will use a set of default values which will let it run but not ate well as it should, as you say a lumpy idle and probably running rich so MPG will suffer and probably peak performance
 
Thanks for the reply mate, any advice what i could do as this one has got me a bit stumped. Yes i am only averaging 29.1 MPG also :o

Cheers, tug :thumbsup:
 
tug said:
Thanks for the reply mate, any advice what i could do as this one has got me a bit stumped. Yes i am only averaging 29.1 MPG also :o

Cheers, tug :thumbsup:
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thats ok isnt it? i only make 27.1 :cry:
 
With it showing zero air flow I doubt cleaning it would do any good, you could try checking for vantage at the connector to see if it’s getting power and also checking the resistance on the sensor pins while moving the flap by hand but I’m afraid I can’t tell you what figures you should be getting, that may help to pinpoint the problem but easiest way would be to try another MAF
 
Thanks for the replies, i have tried 2 MAFS now and no change :( So today im gonna get an auto sparky i know, to test the system to see if he can find fault somewhere in the electrics side of things. This one has me stumped! :idunno:

mr.tourette said:
tug said:
Thanks for the reply mate, any advice what i could do as this one has got me a bit stumped. Yes i am only averaging 29.1 MPG also :o

Cheers, tug :thumbsup:
Click to expand...
thats ok isnt it? i only make 27.1 :cry:
Click to expand...
I thought mine was overly thirsty for a 2.0 but if thats the norm im ok with that :?
 
tug said:
Thanks for the replies, i have tried 2 MAFS now and no change :( So today im gonna get an auto sparky i know, to test the system to see if he can find fault somewhere in the electrics side of things. This one has me stumped! :idunno:

mr.tourette said:
tug said:
Thanks for the reply mate, any advice what i could do as this one has got me a bit stumped. Yes i am only averaging 29.1 MPG also :o

Cheers, tug :thumbsup:
Click to expand...
thats ok isnt it? i only make 27.1 :cry:
Click to expand...
I thought mine was overly thirsty for a 2.0 but if thats the norm im ok with that :?
Click to expand...
Ah..mine is 3.0..apologies I didnt realise that was for a 2.0, no idea what a good mpg is on that model
 
I think zero reading for the MAF is normal (at least that is my experience on INPA) so I'm intrigued when you say you tested Road Warriors other cars and they read normal?? What models are we talking here?

Have a look here... both cars (a 2.5Si and a 3.0Si ) reading zero for HFM sensor airmass...

https://z4-forum.com/forum/viewtopic.php?f=3&t=110050&hilit=maf
 
road warrior said:
You drive it like you have stolen it tug so its not too bad :thumbsup: :rofl:
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Your not wrong there mate :driving:

ph001 said:
I think zero reading for the MAF is normal (at least that is my experience on INPA) so I'm intrigued when you say you tested Road Warriors other cars and they read normal?? What models are we talking here?

Have a look here... both cars (a 2.5Si and a 3.0Si ) reading zero for HFM sensor airmass...

https://z4-forum.com/forum/viewtopic.php?f=3&t=110050&hilit=maf
Click to expand...
I dont know what motor RW's wife drives but RW plugged into hers and it was reading 15% variable, so we thought with mine reading 0% that must be why my zed idles not so smoothly.
But Ph001 i am so grateful to you for pointing me towards those excellent pointers in the thread. So the idle thing is not that bad & i can live with that together with fuel consumption. Overall my zed runs perfect & like most owners on here i just want my zed to BE perfect.

This forum is so informative.

Thanks everyone. Cheers, tug :thumbsup:
 
ph001 said:
I think zero reading for the MAF is normal (at least that is my experience on INPA) so I'm intrigued when you say you tested Road Warriors other cars and they read normal?? What models are we talking here?

Have a look here... both cars (a 2.5Si and a 3.0Si ) reading zero for HFM sensor airmass...#]

https://z4-forum.com/forum/viewtopic.php?f=3&t=110050&hilit=maf
Click to expand...

im sorry but i completely disagree with you - there should be a fluctuation whilst running live data, Tug reading of zero on his 2.0 z4 was unchanged whether the car was running or not - revved up or not.
the clue is in the name.. no airflow - no running engine
testing goes as follows.. start from idle and increase throttle opening while watching MAF reading. Increase should be steadily proportional to RPM change.
 
I suppose you are entitled to disagree with my opinion on whether it’s normal or not but the facts are INPA does not report any reading for HFM sensor air mass on my very healthy 3.0si and another forum members 2.5.

This would also seem to support the fact that Tug has tried other AFM’s with the same result. To suggest there is a fault there would seem a little disingenuous.

I think the AFM signal is actually reported on a different screen called MESSWERTBLOCK1. There is an item there called “luftmasse”

Finally, there is a parameter called "luftmasse gerechnet" in the Valvetronic screen (F5 menu, then shift + F1). Which I believe is the calculated air mass (rather than measured). This is the derived airflow value that the ECU uses when the airflow meter is disconnected.
 
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.
 
road warrior said:
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.
Click to expand...

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".
 
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, :tumbleweed:
 
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 :driving: about 18 miles, and again 0.00 on the live stream :idunno:

So payed a visit to Loughborough BMW specialist indie. Graham, the head tech (top bloke) came straight out (we are old friends which helps 8) ) 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" :lol:

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 :thumbsup:
 
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