Stutter under acceleration ( brand new plugs and coils already fitted )

[PhilNUK]

Hi guys

Had my car serviced a couple of weeks ago... Had new plugs and coil packs fitted at same time.
Noticed last night that when accelerating the car stutters and jumps before continuing to accelerate, also the EML light flashes for a short while after.
Bearing in mind it can't be plugs or coils, what could cause it? I plan on getting any fault codes, but until then be good to hear some opinions.

Cheers

[AJP]

It'll probably be an injector. Getting quite common on these cars now. I used mrinjector.co.uk and he did a very good job. More than the usual ultrasonic cleaning that some services do.

I bought a set of used ones and sent those off for the refurb so I could limp the car about in the meantime - but that's probably not the best idea in hindsight. Big injector misfires will make things quite lean.

[PhilNUK]

It'll probably be an injector. Getting quite common on these cars now. I used mrinjector.co.uk and he did a very good job. More than the usual ultrasonic cleaning that some services do.

I bought a set of used ones and sent those off for the refurb so I could limp the car about in the meantime - but that's probably not the best idea in hindsight. Big injector misfires will make things quite lean.

Thanks for the reply.... I did wonder if it might be injectors.... Worth upgrading to rs injectors if that is the fault?

It's meant to be a big job to get to them isn't it?
I have noticed my mpg has taken a plunge lately

[AJP]

No reason to go for different injectors. Even if there was a benefit you'd need to alter the map to get them to work. K03 injectors have plenty of headroom for anything a k03 turbo can produce, k04 injectors have headroom for anything a k04 can produce... etc. RS3/TTRS injectors would only be of benefit if you were running a k04 hybrid or big turbo. And even then I think you need a custom injector loom etc. Some US k04 conversion maps dictated fitting RS4 injectors IIRC. But again that's a can of worms you need not open.

Yes it's inlet mani off. Not the worst job but it'll cost a bit of labour. What's your spec? Are you k03 or k04? If k04 and you might have plans for tuning there's sense in fitting an RS4 fuel return valve while the manifold is off. It won't need mapping in or anything, and won't be of much benefit until 2+ k04 levels, but if you did end up at that level of tune it's one job ready and done.

[PhilNUK]

No reason to go for different injectors. Even if there was a benefit you'd need to alter the map to get them to work. K03 injectors have plenty of headroom for anything a k03 turbo can produce, k04 injectors have headroom for anything a k04 can produce... etc. RS3/TTRS injectors would only be of benefit if you were running a k04 hybrid or big turbo. And even then I think you need a custom injector loom etc. Some US k04 conversion maps dictated fitting RS4 injectors IIRC. But again that's a can of worms you need not open.

Yes it's inlet mani off. Not the worst job but it'll cost a bit of labour. What's your spec? Are you k03 or k04? If k04 and you might have plans for tuning there's sense in fitting an RS4 fuel return valve while the manifold is off. It won't need mapping in or anything, and won't be of much benefit until 2+ k04 levels, but if you did end up at that level of tune it's one job ready and done.

Ah that's all brilliant info... I have an Edition 30 so K04
Had my eye on a RS4 return valve as an upgrade anyway....
Presume I will get an error code about injectors?

[AJP]

No reason to go for different injectors. Even if there was a benefit you'd need to alter the map to get them to work. K03 injectors have plenty of headroom for anything a k03 turbo can produce, k04 injectors have headroom for anything a k04 can produce... etc. RS3/TTRS injectors would only be of benefit if you were running a k04 hybrid or big turbo. And even then I think you need a custom injector loom etc. Some US k04 conversion maps dictated fitting RS4 injectors IIRC. But again that's a can of worms you need not open.

Yes it's inlet mani off. Not the worst job but it'll cost a bit of labour. What's your spec? Are you k03 or k04? If k04 and you might have plans for tuning there's sense in fitting an RS4 fuel return valve while the manifold is off. It won't need mapping in or anything, and won't be of much benefit until 2+ k04 levels, but if you did end up at that level of tune it's one job ready and done.

Ah that's all brilliant info... I have an Edition 30 so K04
Had my eye on a RS4 return valve as an upgrade anyway....
Presume I will get an error code about injectors?

You might only get a specific fault code if the misfire threshold is exceeded. That will happen eventually with a dying injector but it's probably best not to wait for that to happen. If you have access to VCDS you can log the data live and post up the logs here. I'm not too clued up on that side of it, but there's plenty of info on that on the forum, and plenty of helpful members who can assist. TFSI Mike did the logging for me and then helped along with Pudding and Dan_Fr looking at the logs. Can't tag them myself right now as I'm on Tapatalk, but seek those guys out.

I'll take a punt and say that you could skip the diagnostics, fit some new/refurbed injectors and you'd be all good. But it's probably good practice to get VCDS plugged in and see exactly what's going on.

[PhilNUK]

No reason to go for different injectors. Even if there was a benefit you'd need to alter the map to get them to work. K03 injectors have plenty of headroom for anything a k03 turbo can produce, k04 injectors have headroom for anything a k04 can produce... etc. RS3/TTRS injectors would only be of benefit if you were running a k04 hybrid or big turbo. And even then I think you need a custom injector loom etc. Some US k04 conversion maps dictated fitting RS4 injectors IIRC. But again that's a can of worms you need not open.

Yes it's inlet mani off. Not the worst job but it'll cost a bit of labour. What's your spec? Are you k03 or k04? If k04 and you might have plans for tuning there's sense in fitting an RS4 fuel return valve while the manifold is off. It won't need mapping in or anything, and won't be of much benefit until 2+ k04 levels, but if you did end up at that level of tune it's one job ready and done.

Ah that's all brilliant info... I have an Edition 30 so K04
Had my eye on a RS4 return valve as an upgrade anyway....
Presume I will get an error code about injectors?

You might only get a specific fault code if the misfire threshold is exceeded. That will happen eventually with a dying injector but it's probably best not to wait for that to happen. If you have access to VCDS you can log the data live and post up the logs here. I'm not too clued up on that side of it, but there's plenty of info on that on the forum, and plenty of helpful members who can assist. TFSI Mike did the logging for me and then helped along with Pudding and Dan_Fr looking at the logs. Can't tag them myself right now as I'm on Tapatalk, but seek those guys out.

I'll take a punt and say that you could skip the diagnostics, fit some new/refurbed injectors and you'd be all good. But it's probably good practice to get VCDS plugged in and see exactly what's going on.

Thanks for the info

I got an obd plug and used the Torque app and it found two faults.

System too lean
Misfire Cylinder 2 detected...

Unless there is an issue with the new plugs or coils then I am assuming it's going to be a fuel issue... Injectors like you said.. Going to get it booked in to my local place for them to look into it further.

[ROH ECHT]

If going that far...might as well clean the carbon build-up on the intake valves. Most likely it is all caused by this.

[ZigzGTI]

i had the exact same issue on my previous car.

ended up being the O2 sensor and the MAF sensor which as a result apparently ruined the coilpacks and sparks. so i had to change em all and it was fine after that.

[PhilNUK]

Went in for proper diagnosis....
Failed injector.... It's going in for a replacement and carbon clean next weekend

[AJP]

Went in for proper diagnosis....
Failed injector.... It's going in for a replacement and carbon clean next weekend

Are you fitting 4 new/refurbed ones? I'd suggest it's a good idea to do so rather than just the one that's failed. The other 3 are probably not far behind and it's dead money on labour if you have to take the manifold off again if (when) one of the others gives up in the near future.

[PhilNUK]

Went in for proper diagnosis....
Failed injector.... It's going in for a replacement and carbon clean next weekend

Are you fitting 4 new/refurbed ones? I'd suggest it's a good idea to do so rather than just the one that's failed. The other 3 are probably not far behind and it's dead money on labour if you have to take the manifold off again if (when) one of the others gives up in the near future.

I am actually booked in to replace the failed one with one new one.... The cost of replacing all just wasn't feasible right now. I was tempted to buy 4 used, send them off for a clean and then have them fitted. But Mr Injector (who have been recommended) havent responded to any contact...

[AJP]

Went in for proper diagnosis....
Failed injector.... It's going in for a replacement and carbon clean next weekend

Are you fitting 4 new/refurbed ones? I'd suggest it's a good idea to do so rather than just the one that's failed. The other 3 are probably not far behind and it's dead money on labour if you have to take the manifold off again if (when) one of the others gives up in the near future.

I am actually booked in to replace the failed one with one new one.... The cost of replacing all just wasn't feasible right now. I was tempted to buy 4 used, send them off for a clean and then have them fitted. But Mr Injector (who have been recommended) havent responded to any contact...

That's unfortunate. He did a good job for me. Well fingers crossed the one new one is enough to keep it happy for now.