missfire!!!!!!!!!!!!!!!!!!

millwrx

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i have a w plate a3 1.8 turbo quattro,at high revs the car will missfire but not all the time,seems to be ok if i build the speed up but if i floor it as it gets over 4000rpm it starts to miss,just took it up the road and got it to miss at 5000rpm and it just kept on missing and would not clear,i have replaced the plugs,checked all pipe work.replaced dv vale and n75 valve,cleaned air filter,cleaned out throttle flap,checked coilpacks wiring,had a look at the maf but that looks dry and clean,now the only things i am left with is faulty coils packs breaking down under load or faulty maf,it does seem to me as it is more eletric than fuel surpley problem,anyone had the same fault,the coilpacks are made by hitachi,
 
Unplug the MAF, then go for a drive and see if it still misfires, the car will be running a bit down on power, but if it cures it, that's your problem.
 
jojo said:
Unplug the MAF, then go for a drive and see if it still misfires, the car will be running a bit down on power, but if it cures it, that's your problem.
hi,unpluged it and have just took it for a drive for about 5 miles,did not miss once and drove fine under load and at high revs,so i stopped and pluged it back in and drove it back,and it drove back fine aswell,so not sure now,guessing when the maf is disconected the car runs on the base ecu map setting,dont think its the coilpacks as wouldnt these break down pretty much all the time
 
I'm guessing you have a duff MAF anyways, did you notice more power when you plugged it back in?, I can certainly feel the power difference with a healthy MAF and a duff one.
 
jojo said:
I'm guessing you have a duff MAF anyways, did you notice more power when you plugged it back in?, I can certainly feel the power difference with a healthy MAF and a duff one.
not really it felt about the same to be honest,
 
Just don't try saving pennies and buying a non Bosch part off fleabay! Trust me it doesn't solve the problem, buy a genuine Bosch part!!
 
Jampublic said:
Just don't try saving pennies and buying a non Bosch part off fleabay! Trust me it doesn't solve the problem, buy a genuine Bosch part!!
just been looking on there,found a place that sell genuine ones,the thing being that the part number on mine is 06a 906 461d,and the one they are selling ends with a c,will it still be ok as what does the last letter mean
 
millwrx said:
just been looking on there,found a place that sell genuine ones,the thing being that the part number on mine is 06a 906 461d,and the one they are selling ends with a c,will it still be ok as what does the last letter mean

Well its your choice, I rather pay the money and get the genuine Bosch part!

When my MAF went wrong its shows a missfire on VAG.COM, this remained even when I switched the coil packs round. I would go after the MAF first, where are you based?

You need to find someone local to you, so you can try to swap out your MAF with another and even find someone with VAG.COM would make your life easier!

Good luck
 
Jampublic said:
Well its your choice, I rather pay the money and get the genuine Bosch part!

When my MAF went wrong its shows a missfire on VAG.COM, this remained even when I switched the coil packs round. I would go after the MAF first, where are you based?

You need to find someone local to you, so you can try to swap out your MAF with another and even find someone with VAG.COM would make your life easier!

Good luck
not convinced that it is the maf,coilpacks i would have thought would have given the fault pretty much all the time under hard load ,just thinking that it could be the pickup sensor?
 
I have no idea's about the pickup sensor, swapping the MAF out would remove it from the list of possible problems!
 
have just been for a drive and got the fault,stopped the car,disconected the maf and it still had the fault so that rules that out,i do have a hand held tester that records fault codes and that is showing no stored faults,it is a electric fault i'm sure due to how it miss'es when the fault occurs,runs fine if i dont drive it hard,but as soon as i really give it some stick up the gears it seems to miss,guessing that vagcom will fit on my car and is just a fault code reader like the one i have but perhaps abit more indepth?
 
So you are not getting any faults codes from you car at the moment? Just getting a miss under power!
 
Jampublic said:
So you are not getting any faults codes from you car at the moment? Just getting a miss under power!
yes thats right,it does have a set of bosch super4 plugs in it and they have covered about 10000 miles but did look ok when i took them out the other day,now thinking of replacing the plugs and buying one coil pack and trying that,anyone know the correct ngk plugs and gap for it
 
If its a coilpack surely it will throw up a fault code, like a missfire on cyl 1 or 2 or 3 or 4!
 
Jampublic said:
If its a coilpack surely it will throw up a fault code, like a missfire on cyl 1 or 2 or 3 or 4!
thats what i would have thought,just dont want to go and buy parts that i dont need and waste a load of cash,needless to say my local audi dealer is never that helpfull
 
nickelvery said:
Where do you live willwrx?
worcestershire in a place called upton-upon-severn,you may have seen it on the tv when the floods were up
 
Jampublic said:
If its a coilpack surely it will throw up a fault code, like a missfire on cyl 1 or 2 or 3 or 4!

My coilpack failure didn't throw up any codes initially. It was only when I went out a couple of days later and really gave it some on the motorway that the engine light came on for a few seconds and it logged a fault, so yours might not be logging? The problem here is that without a log you can't prove it or identify which cylinder its misfiring on.

Just to be safe, I wouldn't drive it much without sorting the problem. If it is a coilpack then there's a risk your passing unburnt fuel through to your cat which can damage it.
 
Funky_Junky said:
My coilpack failure didn't throw up any codes initially. It was only when I went out a couple of days later and really gave it some on the motorway that the engine light came on for a few seconds and it logged a fault, so yours might not be logging? The problem here is that without a log you can't prove it or identify which cylinder its misfiring on.

Just to be safe, I wouldn't drive it much without sorting the problem. If it is a coilpack then there's a risk your passing unburnt fuel through to your cat which can damage it.

Millwrx is getting a missfire under heavy accelaration and is not getting any fault codes coming up! How long before a faults will log and as you said Funky_Junky if it is a coilpack he is messing up the cat if he continues to drive it! :faint:

Millwrx worthing trying if VAG.COM see's any faults or time for a stealer!

Good luck
 
millwrx said:
worcestershire in a place called upton-upon-severn,you may have seen it on the tv when the floods were up

Maybe its water damage ;)

On a serious note i'd try getting it vagcom'd. If it doesn't throw up any errors then buy a single coilpack (£30 and the most up to date version should have 'R' on the end, my dead one was 'J') and try swapping it in each cylinder until it stops hesitating. It'll be a bit of a pain to do, espcially on cylinders 3 and 4 as there's some other bits to un-screw to get access, but its easy enough.

If it turns out not to be a coilpack then just keep the part - one will go eventually!

Some people change all four when one goes, but that depends if you've got £120 to spare. Good luck mate.
 
cheers all,have replaced the plugs for ngk pfr6q and will be trying it later,aslo ordered one coilpack today so if its not the plugs then i will try swaping them to see if its that
 
have just tryed it up the road and its the same,now hoping this coil pack will sort it,like i said before its only slight sometimes but other times it can be quite big which will stop the engine from reving past a certain rpm(around the 4 to 5000 rpm)also thinking of getting a new fuel filter when i pick the coilpack up
 
millwrx said:
like i said before its only slight sometimes but other times it can be quite big which will stop the engine from reving past a certain rpm(around the 4 to 5000 rpm)...

Sounds identical to my symptoms, good luck with it!
 
replaced the coilpacks today and its still the same,still have no fault codes stored,thinking perhaps it might be a blocked/sticking injector?to be honest i running out of ideas,does seem to be alot of threads on here with the same fault but no one has got to the bottom of it,thinking it might be a program software fault from audi?????????
 

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