I have recently noticed a minor annoyance with my QV that I would appreciate some advice on.
It is quite hard to describe exactly what it does but I will try. When I accelerate from cold, the engine fails to deliver the power I am asking for. If I let the throttle off and reapply, often it will accelerate as it should but if I keep my foot in, it labours for a bit then delivers the correct power.
It still accelerates throughout but just feels like everything in the engine is moving in slow motion or struggling through soup. It feels like fuel is not being delivered in the requisite quantity.
Once warm, it is fine.
Does this sound like classic air flow meter issues?
If so, where would I find the b**ger to give it a clean?
Also, is a MAF just an AFM for dyslexics?
It does sound like either MAF or Lambda by your description, probably more MAF. Does it ever 'judder' while driving?
AFM and MAF are the same things.
It can be found just above the battery and it looks like this with the induction piping connecting either side:
You probably already seen numerous post on here about disconnecting the AFM/MAF so I suggest you do this and take the car for a drive to see if it makes a difference. You will find it in the pipe that goes from the airbox on the right-hand side of the engine to the throttle body housing. The electical connection is on the top. Just simply unplug it. If this doesn't work then try the same test of driving the car with the lambda disconnected instead.
Anyway, to answer your question an AFM's / MAF's, AFM's use a fairly crude method of measuring the air flow while MAF's use a more sophisticated and precise way of measuring the air flow. They each work in the following way...
AFM (Air Flow Meter)
This just measures the flow with a kind of crude spring-loaded 'door' mechanism where the door operates a variable resistor. The value of resistance is set on the variable resistor by the amount the 'door' is open by and this resistance is used to determine the air flow.
MAF (Mass Air Flow)
This uses 2 wires, one cold and one heated. In very basic terms, the passing of air over the wires cools the hot wire and the difference in temperature between the hot and cold wire is used to determine the air flow.
It does judder a little too...So, I'll take a look.
On some of the other threads, people talk about 'not touching the wires', why so?
I'll go for AFM first but, if no joy, I take it the Lambda is tucked away atop the exhaust manifold, close to the engine?
Thanks, the black one to the left of the white one? (just right of centre).
GE's pic is for the later phase two (plastic top) engine. If yours is the earlier ally top engine the lambda connection is under a black cover against the bulkhead, but it has exactly the same connector.
Don't touch the wires on the MAF because you can get grease on them from your finger which can damage them further
I can't believe I am having to post this but I cannot get the clips undone that attach the intake pipes either side of the AFM
They seem a fairly simple clip together mechanism but they have a sort of channel with a sliding tab in it. They have CLIC-R (IIRC) written next to them. A glance around the engine bay demostrates that I am going to need to work the pesky little b**gers out - is there a trick to them?
I feel slightly retarded but I don't want to risk brute force as it I break anything the only chance I would have of replacing it today would be Halfrauds....
Right, I've had the AFM out, sprayed it all over with Halfords Electrical Contact Cleaner and given it a rub with cotton buds. No dirt or grease appeared to come off it and it looked in good nick so I put it back and went for a drive.
This is where it got interesting - the problem (sluggish acceleration and a 'labouring' feeling) was even more noticeable than usual. So, I pulled over and disconnected the AFM...she then ran really sweetly. That's it I thought, it must be bu**ered.
So I pulled over and plugged it back in...the problem didn't return. So, I am thinking that the problem only seems to exist when cold (once I had run it with the meter disconnected, it was nice and warm by the time I plugged it back in).
Thinking back to my first test yesterday, I disconnected the meter and drove it from cold and it was fine.
So, it is likely that the AFM could have difficulty ONLY when the car is cold?
Also, is it likely that the car feeling so good is simply a result of it running rich - am I going to be disappointed with a new AFM?
It was so sweet with the meter unplugged that I am almost resolved to buy a new one anyway but I would like to be sure first!
As for those clips...ridiculous creations, I intend to replace all of them with jubilees ASAP.
When you plugged the MAF back in did you switch the engine off first or do it with the engine running? Regardless though, if she did run fine both cold and hot with the MAF disconnected then it is definately the MAF which is the cause of your problem.
I believe the reason for those ridiculous clips is not just to make life difficult for us DIYers but more for the reason that they only have one 'closed' setting so when clipped up they put the correct amount of pressure on the joint as they can't be overtighted (unlike jubilee clips which can)
The temp sender unit could be the culprit... mine has just been changed due to lumpy running.
Engine was off each time I plugged/unplugged.
The more I read, the more I become convinced it is the MAF.
I am going to do some further tests and give it another good clean (I cleaned it in situ so I'll be a bit more thorough next time) before I shell out £120 for another.
However, for future reference, am I right to assume that any garage with a decent diagnostics machine could spot whether the MAF, the lambda or the temperature sender are faulty?
I believe the MAF only shows up as a fault on the diagnostics tester if it has failed completely, not if it is still working (even if so badly). Not sure about the other sensors...maybe the same? The ECU usually logs a fault on a sensor if it detects an open circuit on that sensor (i.e. disconnected) or the resistance on that sensor falls outside the expected tolerance range (failed or failing sensor).
have you got a alloy or plastic top engine
I have been looking at the same things, with regard to removig the MAF there seem to be a couple of alan key bolts, but with an upright piece preventing the use of a regular key to remove them. Is this a special tool job too? if so, where can they be bought from?
If I were to just unplug the Lamda, would that be a resonable diagnostic test? local mechanic mate of mine reckons that a lamda is likely to cause rough running/jerkyness, the MAF will cause sluggish, gutless performance.
I have a plastic top.
Pardon my ignorance, where does the temperature sender live?
Also, was that £12 from Alfa & does anyone happen to have a part no.?
Demanding little b**ger aren't I?
I can feel for you, mine's been doing the exact same & it's been driving me mad for weeks/months....just read through the post, tried it out & hey presto everything seems fine - guess the real test is in the morning when she's cold again!!!
Anyone know of an alternative to proper contact cleaner? Like WD40 or something, I've got plenty of that!!!
One question for the more initiated out there, should my injector light remain on if I've disconnected the MAF? It normally goes off with the Airbag Light but stays on now.....?
Giallo - have you put together a catalogue of pictures of your entire car? Everytime I ask a question, you have a photo of the relevant part!
Obviously, I am not complaining - I am simply amazed (and thankful ) at your dedication/efficiency!
"I always believe in the old cliché that a picture paints a thousand words "
Damn right it does! Especially yours - I have always found that Haynes pictures left a lot to be desired, partly because they are B&W but also because the don't show the wider 'context' so you often cannot work out what you are looking at. However, I am finding your assistance priceless
Ordered my sensor today so I should know this weekend whether I need to replace the MAF or Lambda.
Anyone know what the cost will be if the Lambda is the culprit (and is it as easy to change as the other bits)?
Once again, thanks very much
Dont know if it helps but i asked kind of the same question on the thread "cars hesitant for the 1st mile". I was told hear that this is quite normal and its the engines way of not letting you thrash it hard for the 1st mile. Im quite new to alfas, had it about 2 months but the cars always been the same.
worth a look matey.
heya guys ive been reading this threat with interest.
i have a similar problem as the car is juddery while driving,it is sometimes a violant judder.
it seems to be worse when warm,
my engine is the old boxer 1.6 type(not as posh as you guys )
any help would be gratefull
wish i read these earlier .. unplugged my MAF today to test on the drive to work. and the hesitation at full throttle i have was nowhere to be seen, the car was not losing power on hills it just roared up them. was a bitch at stable revving in the border queue so plugged it back in when i stopped and vowed to get a replacement.
so first question , will running with a non working MAF mess up anything else? its been slow over the months but nothing major.
so went the the whole faq tonight and found some other things out like why the clutch peddle sometimes doesnt return and checked the slave clyinder location and sure enough its got a puddle beneath it.
also planning to change temp sensor as it seems to cheap not to.
also after checking this part of the site i have discovered a shopping bill of £500 from shop4parts ( not including HP steering hose from pump) of things to do. its going to be a happy spring time, with so much to do i can now leave the wife to rearrange the furniture whilst im down in the garage doing good and drinking beer and shouting and fixing the motor, like men do.
the £500 is based on ;
S4P1323 - Rocker Cover Gasket £20.36 £20.36
S4P1056 - Air Flow Meter £125.64 £125.64
S4P641 - Camshaft Advance Variator £79.02 £79.02
S4P1899 - Timing Belt Kit £86.67 £86.67
S4P905 - Spark Plug (14mm) £8.68 £34.72
S4P906 - Spark Plug (10mm) £8.68 £34.72
S4P184 - Clutch Slave Cylinder £30.10 £30.10
for UK Mainland £7.95
and need a new aux belt, and they will all have to be sent to sunny spain.
cant believe i spent 120 euros on brake pads at the local alfa/fiat dealer when i could have got them for £24 and then paid shipping to spain at a cheaper price!!! you live and learn i guess. and before you ask , local motor factors could not supply.
oh, and a replacement passenger door mirror (LHD) as it seems that holds the outside thermostat for the auto climate control thingy. that got totally wiped out via a door opening whilst my wife was on her way home. it was somebody elses van door that opened whilst parked up on side of the road ... so she declines to fund it. and funny enough so did the van driver!
great website still . just wish i used it more and checked all the topics, threads and areas first
now i think of it,this section of the forum hates my wallet!!!!
And if you have the plastic top engine, you can get a genuine Bosch MAF at almost half the cost that Shop4Parts are charging (even with postage costs) by getting it from Italy...
discounts? yet another part i have not seen . . . yet ty
that said gazzafisher did offer some tooling for the maintanence at a wonderful price ( discount due to being part of this forum) i have yet to finish the deal on. my fault not his. been busy with moving house and money issues. but soon to complete as cambelt will need a change this august-ish time
2nd edit due to seeing a MAF at 70 euros!! happy days ahead muchos gracias compadre
as far as my junior knowledge goes ... its a standard 1.6 ts with a junior bagde on the side skirts and tail and the seats have "junior" embrioded (sp) in them
this may seem a simple question i already know the answer to but ill ask it anyway.
with the MAF unplugged: at idle the revs fluctuated like crazy .. and on pulling up through the revs .. e.g 3k in first/second gear going to 4k it kinda resists for an instant blurts for a bit, then kicks in. any release from the throttle in low revs gives a juddery feeling to the drive like running over bricks
im guessing the MAf is unplugged so ecu is throwing the "safe value/default value" of fuel in and other sensors are having fun trying to catch up. is this ok or is there something else that might be out of kilter? as in, regardless of maf in or out (is it just the fuel consuption that goes up( at 63p a litre it isnt that bad but would be nice to keep it as low as possible) , and the crazy reving is something else entirely?
when i put the MAF back in the revs still fluctuate, but very mildly.
side note; i have carefully cleaned the MAF on the weekend and have got some improvement. but not enough to stop me getting a replacement.
forgive me if that made no sense as the tuesday night vodka and cod4 mix are doing its magic, just scared theres more problems ahead as wife is watching her shoe shopping fly out the window for working car parts list, a list that seems ever growing.
hi there if can any.one.help.me with this ..my car was always sluggish and wont be fine at all ..i have 146 ts 2.0 with maf 4pins i fit it yesterday a maf for volvo same number but the 3 ending number is different ..any way the car is alive again like new is that fine? with the ecu ! !!! please some suggestion i'll be thankfull
hi again the part number is 280217102 for volvo the same one for hundai accent model 1995
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)