MAF showing 0% airflow

tug · Post by **tug** » Sun Jul 21, 2019 7:43 am

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

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.

Thanks for any help/advice you could share. tug

Oh and we tested RW's other cars and they all read normal airflow

Chippie · Post by **Chippie** » Sun Jul 21, 2019 8:46 am

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

tug · Post by **tug** » Sun Jul 21, 2019 9:18 am

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

Cheers, tug

Smartbear · Post by **Smartbear** » Sun Jul 21, 2019 4:15 pm

Can you swap the maf over from another 2litre to see if it sorts it out?

Rob

andystone · Post by **andystone** » Sun Jul 21, 2019 4:37 pm

Is it worth cleaning these things?

mr.tourette · Post by **mr.tourette** » Sun Jul 21, 2019 6:41 pm

tug wrote: ↑Sun Jul 21, 2019 9:18 am 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

Cheers, tug

thats ok isnt it? i only make 27.1

Chippie · Post by **Chippie** » Sun Jul 21, 2019 7:31 pm

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

tug · Post by **tug** » Mon Jul 22, 2019 5:57 am

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!

mr.tourette wrote: ↑Sun Jul 21, 2019 6:41 pm
tug wrote: ↑Sun Jul 21, 2019 9:18 am 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

Cheers, tug
thats ok isnt it? i only make 27.1

I thought mine was overly thirsty for a 2.0 but if thats the norm im ok with that

road warrior · Post by **road warrior** » Mon Jul 22, 2019 9:44 am

You drive it like you have stolen it tug so its not too bad

mr.tourette · Post by **mr.tourette** » Mon Jul 22, 2019 10:02 am

tug wrote: ↑Mon Jul 22, 2019 5:57 am 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!

mr.tourette wrote: ↑Sun Jul 21, 2019 6:41 pm
tug wrote: ↑Sun Jul 21, 2019 9:18 am 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

Cheers, tug
thats ok isnt it? i only make 27.1
I thought mine was overly thirsty for a 2.0 but if thats the norm im ok with that

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

ph001 · Post by **ph001** » Mon Jul 22, 2019 12:56 pm

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...

viewtopic.php?f=3&t=110050&hilit=maf

tug · Post by **tug** » Mon Jul 22, 2019 6:46 pm

road warrior wrote: ↑Mon Jul 22, 2019 9:44 am You drive it like you have stolen it tug so its not too bad

Your not wrong there mate

ph001 wrote: ↑Mon Jul 22, 2019 12:56 pm 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...

viewtopic.php?f=3&t=110050&hilit=maf

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

road warrior · Post by **road warrior** » Mon Jul 22, 2019 11:47 pm

ph001 wrote: ↑Mon Jul 22, 2019 12:56 pm 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...#]

viewtopic.php?f=3&t=110050&hilit=maf

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.

ph001 · Post by **ph001** » Tue Jul 23, 2019 7:28 am

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.

road warrior · Post by **road warrior** » Tue Jul 23, 2019 9:51 am

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.

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