MAF cleaning

[irvind]

Thanks again jubjub, wicked instructions! The second allen bolt is extremely hard to get at so I'll go looking for a suitable tool for that. Unless anyone knows a 2-inch midget with the strength of a grown man..

[Pete_RS2]

Might be easier if you unclip the airbox cover & remove that.

[ericd]

Irvin,
if u'r still having problems getting the maf off & cleaned I'm down the
'road in Ayr, so I'd be happy to give u a hand if you need it...

[irvind]

Thanks Avant S2, that helped loads. MAF removed and cleaned. Couldn't get the second allen bolt off so just scooshed in some IPA with a spray nozzle, hopefully that'll do the trick.

@ericd, I'll send you a pm..

[Greg_S]

If anyone needs to get hold of IPA i noticed that CPC have a tin of it on special offer at the minute.

Greg

[RS2.pt]

I cleaned my maf plug with common brake cleaner and its been fine since! high recomend it!

hi
are you talking about cleaning the MAFs plug or the internal MAF wiring? cause I always thought that internal MAF wires were to avoit to touch, in order to avoid damagin it. plus I was told that when you turn of the engine it self cleans burning the dirt on wires... dont know if I am wrongly informed...

[Lee]

They are talking about cleaning the sensing wire. It is delicate but can be cleaned with the correct solvents. It involves a copious spraying with something like Isoprpyl-Alcohol (IPA).

[horvathg]

plus I was told that when you turn of the engine it self cleans burning the dirt on wires...

I don't think it works like that. In this case you would have to raplace it often, as you replace a bulb because heating a cold wire systematically kills it in no time. Again, street dirt would require rather high temperatures to get rid off. It is possible to rinse the wire with non pressurized sprays like houshold precision contact spray or my favourite, the CRC videorecorder head cleaner. Basically medical quality IPA that leaves no trace when dry. I don't remove the filter box, just loosen the hose clip and spray in with a nozzle directly on the wire for some 20 seconds. It works quite well.

[auditude]

plus I was told that when you turn of the engine it self cleans burning the dirt on wires...

I don't think it works like that. In this case you would have to raplace it often, as you replace a bulb because heating a cold wire systematically kills it in no time. Again, street dirt would require rather high temperatures to get rid off. It is possible to rinse the wire with non pressurized sprays like houshold precision contact spray or my favourite, the CRC videorecorder head cleaner. Basically medical quality IPA that leaves no trace when dry. I don't remove the filter box, just loosen the hose clip and spray in with a nozzle directly on the wire for some 20 seconds. It works quite well.

I have no reason to doubt the manual and other information that say the MAF wire is heated when the ignition is turned off to burn off contaminants. They warn not to disconnect the MAF or battery immediately after shutting off the ignition because it interrupts this process. Also the wire is heated to a lesser degree when the car is running, which is how it detects the mass flowing across it, by varying the voltage necessary to maintain a set temperature in the wire, so it's not like heating a cold wire. It's increasing the heat in a heated wire. I don't think the wire in a light bulb is identical to the MAF wire, which I would imagine is intended to last the life of the car, heated in this manner.

[horvathg]

I have no reason to doubt the manual and other information that say the MAF wire is heated when the ignition is turned off to burn off contaminants. They warn not to disconnect the MAF or battery immediately after shutting off the ignition because it interrupts this process. Also the wire is heated to a lesser degree when the car is running, which is how it detects the mass flowing across it, by varying the voltage necessary to maintain a set temperature in the wire, so it's not like heating a cold wire. It's increasing the heat in a heated wire. I don't think the wire in a light bulb is identical to the MAF wire, which I would imagine is intended to last the life of the car, heated in this manner.

Take a close look at the wire when not rinsed for some two-three months. It lacks shine completely and is blackish like the fine wire mesh in the intake side of the MAF. If you touch the mesh, your finger gets black with dirt. The same should be on the wire, too. Didn't intend to convince you on anything, though. However, there is no voltage measurable at the MAF connector after ignition.

[martin richards]

Hello, I'm new to all this and i'm trying to improve my fuel acconomy, currently 10-15 mpg once hot and keeping revs under 2500rpm.
I have followed this procedure, soaking the MAF in IPA. Have changed lamda sensor for new expensive one, changed throttle position sensor. car reads no faults. Changed radiator, temprature reads 2 notches below 90c around town and 3 on a run. Changed plugs, ignition coil packs and awaiting( on friday to change plug connectors, which are not in best of condition).
when i got the car 4 months ago it would do 25-30 mpg on a run and since then i have spent a fortune, but the cars mpg is dropping like flies. A tank of juice (97/8 RON) in under 200 miles.
Would post my own tread but can't seem to do it?
Any advice would be great.
Thanks.
Martin

[s2driveruk]

Martin,

Yep, depending on how you drive you should see over 300 on a tank so there is definately a problem of some kind. What kind of Lambda have you bought?

My poor running (read rich) was down to the lambda being broken and its been back to 23-26mpg ever since depending how heavy my foot is

David

[martin richards]

Not sure it was put on by my local motorsport garage, who to me seem good, just that their use to fast jap and BMW metal not Audi. He told me, this was 8 days ago that this was a expensive one (£105) because cheap one's dont last and he has never had faults with these on Skylines and the such. Would knacked plug connectors or low water tempature cause any faults? The car drives fine, but at that fuel comsuption not with me, for long.
Thanks David.
Martin.

[s2driveruk]

personally I would get the appropriate Bosch lambda for the S2 which is about £50. If you have low water temp then you should also change the multi function temp sensor which is hanging from the underside of the water/coolant rail. You can find this by following the black hose which goes from the top left of the main radiator to the block, i think this does affect the MPG too.

HTH,

David

[martin richards]

David, i have no yard stick to measure my temprature. Should it read 90c, once at running temprature?
Thanks.
martin