Rough idle (again)

[pudding]

If the engine behaved like that pulling the maf, it was using it to measure load, which suggests it's fine.   If you unplug the maf and nothing happens, the ECU is not using it and basing load measurement from the throttle instead.....which is not ideal, but it works.   Try pulling the battery for 30 mins which will force the ECU to recheck and relearn all of the sensor inputs.

Needs to be 30 mins minimum because if it's less than that, sometimes the driver's side door module won't work.  Which will need another 30 minute battery pull!  Weird I know, but these cars are quirky like that.

[Graham1990]

Does anybody know if there is a place that could recondition my injectors? Is there such a place or would it be a case of buying new ones. (If they are the problem).

[pudding]

You can send them off to someone like Mr Injector.  New ones are about £100 each from VW.

[Graham1990]

Ok, thanks mate. I’ve just found out one of my mates has vagcom. Do you know how to check if the injectors are working properly with vagcom?

[pudding]

That isn't a check you can do with VAG-COM unfortunately.   The only way to test them properly is on an ASNU type test rig....



I would get it smoke tested and compression tested before investing in injectors.    The MAF also plays a key part in idle quality, so perhaps get hold of a can of MAF cleaner, or electrical contact cleaner.  Give it a blast and see if things improve. 

[Graham1990]

That isn't a check you can do with VAG-COM unfortunately.   The only way to test them properly is on an ASNU type test rig....



I would get it smoke tested and compression tested before investing in injectors.    The MAF also plays a key part in idle quality, so perhaps get hold of a can of MAF cleaner, or electrical contact cleaner.  Give it a blast and see if things improve.

Ok mate, It’s getting smoke tested Saturday 10th March all being well. Is there anything I can look for on vagcom that would help my cause finding the rough idle and or the random appearing p000a code? Thanks for your advice 👍👍

[pudding]

Process of elimination mate.  I'm in the same boat as you.  Slower than usual and rough idle, performance is down and some surging on part throttle acceleration.

Everything looks fine in VCDS and I've also replaced everything you have, so it's time to investigate the mechanicals.  Cylinder compression, turbo wear, fuel pump(s), boost leaks etc.

Given everything you've replaced, I'd be inclined to do the same!

[Graham1990]

@Pudding it’s a pain in the arse 😅. I’ve also noticed sat on tick over it sits at 800 or 900 rpm which ever it feels like. Never higher or lower and it doesn’t flutter it will either sit bang on 900rpm or bang on 800rpm. Either way the headlights lights are constantly flickering. That annoys me lol. Oh well if you find out your problem let me know what sorted it. If I cure mine before that I will let you know what cured mine. Thanks mate.

[pudding]

Yeah tell me about it.  All the love and attention rewarded with strops!!  Cars are like women!!

Mine's been like that too.  The 900ish rpm is smooth, but when it drops to 800ish, it's lumpy!  I blasted the MAF with some MAF cleaner after work, so I'll see if that helps in the morning.

Flickering headlights could be a clue on yours.  Do the interior lights pulsate slowly with the engine running?  That's a sign of a dying alternator diode pack, which is a cheap fix at an auto electricians vs £400 odd for a new alternator from VW!  A dying alternator / weak battery would almost certainly cause your symptoms.

[Graham1990]

Yeah tell me about it.  All the love and attention rewarded with strops!!  Cars are like women!!

Mine's been like that too.  The 900ish rpm is smooth, but when it drops to 800ish, it's lumpy!  I blasted the MAF with some MAF cleaner after work, so I'll see if that helps in the morning.

Flickering headlights could be a clue on yours.  Do the interior lights pulsate slowly with the engine running?  That's a sign of a dying alternator diode pack, which is a cheap fix at an auto electricians vs £400 odd for a new alternator from VW!  A dying alternator / weak battery would almost certainly cause your symptoms.

The interior ones aren’t so bad but they do flicker as well yeah. Battery is fine it cranks the engine over really easily and will do for ages as I tried to start it for ages after I was messing with the maf. Next Saturday is the smoke test and I might see if I can get it compression tested at the same time. I never have much luck with cars 😅

[Graham1990]

@Pudding do you know how To log misfires on vagcom ?? If so could you write a step by step how to for some one who has never used vagcom like me 😅. I would really appreciate it 👌

[pudding]

Google is your friend and pocket library mate - "misfire counter tfsi vcds" brings up everything you need to know!

[Pesky jones]

I've got a strong feeling its air leak related. Which your upcoming smoke test will highlight :)

Also, you might have a number of leaks, so dont stop the smoke at the first leak. For example, if introduced at the inlet you might have some smoke egress from the MAF housing which wouldn't be significant enough to cause your issue. If you let the smoke continue round, you might find a much more significant leak at say the turbo outlet pipe or a bayonett coupling at the intercooler etc.

[Graham1990]

I've got a strong feeling its air leak related. Which your upcoming smoke test will highlight :)

Also, you might have a number of leaks, so dont stop the smoke at the first leak. For example, if introduced at the inlet you might have some smoke egress from the MAF housing which wouldn't be significant enough to cause your issue. If you let the smoke continue round, you might find a much more significant leak at say the turbo outlet pipe or a bayonett coupling at the intercooler etc.

Ok, hopefully you are right and the smoke test reveals my problem! Thank you for the advice, it’s appreciated and very much needed 😆I will let you know how I get on 👍

[Graham1990]

Morning all,  just had the engine smoke tested and there is a leak from one of the little plastic pipes that clip onto the pcv! Fingers crossed replacing this will solve my problem. Does anyone have recommendations on getting rid of the pcv? Just buying a blanking kit and putting that on. Or should I just replace the plastic pipe and keep the pcv all how it is ?