Airflow meter expertise needed

[OcTaLL]

As soon as I loostened the center part and moved the blade thingy right on the track(remember at "Zero" it was nearly 1/4 from the right of the edge on the track), my fuel consumption already came down to 16L/100km. Pretty good from 35L/100km.

This is how I think the MAF works and some technical foondy's knowledge would be great on this:
When the needle is at "zero", just enough petrol is injected to keep the car at idle.
As soon as the needle moves left on the track it tells the ECU to inject more and more till it reaches the far left and "max" as per computer settings.

As mine was at "zero" nearly 1/4 on the track at idle it was injecting as much petrol as it would when the car is at 1/4 throttle.
When the needle was moved right to sit at a lesser degree on the track less petrol is injected already.

voila, fuel consumption sorted for now.

Just finding out if all is OK with system, will get car back from mech this week.

Lvdm: will contact you as soon as I get the car back, then we can see if my MAF is 100%.

How do I loosten the needle from the center thingy to change the landing of it on the tracks.

[iceblue]

I actually had mine open yesterday. Should have taken a picture, but mine sits all the way to the right when the car is off.

[GolfMad]

Hello GolfMad. The answer is: very carefully. Basically you cut it all the way around with a blade, and then start forcing it. Note: it does not matter much if the edge cracks in places. It seals on an inner-edge. I reworked my AFM cap edge with supa-glue and sandpaper before assembly. You cant even see that it's been tampered with . Re-seal AFM with silicon before re-assembly.

If you search for your symptoms, I think it's called 'over-run'. Do you have a decent fuel consumption? If not you may be running rich. you can check the fuel rail pressure and CO. I've reset my digifant to get rid of a similar (but much less severe) overrun problem. I do have to get the CO properly reset now though.

ps: I'm very new to this, with very limited experience, so follow advice at your own risk!

Thanks LvdM - ill try and open it again this afternoon after work, I am just very carefull because you know what they cost, and I sometimes fix things that arent broken

[iceblue]

Mine came off very easily. I put a flat screwdriver in it and twisted it. Did this till it was loose enough to grip and then just pulled it off.

[LvdM]

Hello OcTall, I'm just wondering... How did the wiper arm on your AFM get moved that far up the track? Is there any evidence that the AFM has been opened before? Was the wiper arm loose? Any other mechanical damage to the AFM (e.g. can the flap swing past 0). I'm having difficulty immagining how this problem came about.

[OcTaLL]

It has been opened before yes, when I opened it, the needle was about 5mm from the right end of the track. You can see on the photo that when on full throttle it actually over ran the track by a few mm, now it's just onto the track and doesn't run off it.

[GolfMad]

Tried again yesterday, but no go !!! mine doesnt want tu budge, and if I force it anymore, it will break the plastic casing.... I give up.....

[OcTaLL]

Mine also is broken in some places as it was opened before, you just silicone it closed again. These units are suposed to be sealed but I guess it's just to make our lives complicated...lol. Just use a flat screwdriver and wedge it till it pops open in some places, like a paint can it will open eventually.

[OcTaLL]

Got the car back yesterday. It was idling really strange, it would rev up by itself and idle really odd. Took the cover off from the MAF again this morning, this time I loostened the whole part that latches onto the shaft. Moved it up so that the needles can run a new track.

Also I took the idle control valve off, cleaned again and sprayed a whole lot of tool in a can into it and literally washed it with that and blew it through till the oil that came out the other end was much cleaner. Started and voila, it hasn't died when braking at stops. It still idles pa-pa-pa-pa and drives real smooth now.

And here's the best part: Fuel consumption is down from 30L/100km to 9.9L/100km, boy am I chuft!

Will clean it again in a while as it just sometimes gets stuck, must be the idle control valve that needs lube for opening and closing

[LvdM]

Good result! Seems both our Digifants are back on the road. Did you have The CO set? If so, can you suggest a mechanic with CO detector in PE?

[OcTaLL]

Hi there, no not yet. I was planning on having it dyno'd at GMP Racing, R450, guess they'll do it then. Have to sort my exhaust out 1st, it has a cracked branch, any idea where I can take it. You know the guys, they'll just say, replace, replace. I'll be saying repair, repair...lol

oh ya, try Will at 079 170 5866, he does alot of electrics on VW, sure he can help, he's just around the corner here in Lorraine. I'm going to him next week.

[OcTaLL]

When driving slowly and foot very light on petrol car would idle and not stall when clutching to stop streets. When foot is little to heavy on petrol car would not idle and stalls. I'm thinking it's just the MAF thats faulty because it only works fine when it is dealt with lightly.

[LvdM]

Hi OcTaLL
I'm no expert, but it doesn't soud like AFM. Bring it round, we can put 5V on and measure with a multimeter while operating the flap by hand.

[D3co]

I also have the same problem, my golf 3 gti has black smoke and its fuel consumption is very high and when i hold my acceleration steady it is vibrating a little and when i rev it ends near the red sign doesn' wanna clog, is it dead or it just needs to be adjusted