Hi all,

I have a fl octy vrs.which has developed as described a kind of misfire/stutter as I accelerate. 

Done a little research and changed coil packs and plugs( uprated off awesome) which has improved it a lot, as you could hear the misfire while car was ticking over and pulls

more smoothly but there is still something not right as I can still feel a slight stutter hesitation when accelerating.

There are no warning lights on.

Could anyone suggest what I could do next please.

Carbon build up on the intake valve. whats your mileage?

Oil seperator /breather unit on top of camcover see if it's sucking in air. It breaks up inside and allows unmetered air in causing a weak mixture. Happens a lot and gives no fault codes. Causes the misfire.

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Thanks for replies.

The car has got high miles 118k and I have tried stp petrol cleaner.

is the breather unit fault something I could do myself bearing in mind I have no mechanical silks at all or should I take to a professional?

Is the breather unit the PCV valve?

Edited 7 September, 201510 yr by planehazza

That breather is from the TSFI. Yours is TSI. To test yours is faulty. Unscrew the oil filler cup while the engine is running, you should get a sucking air effect into the cup and engine should stutter. You'll know yours is working.

At the millage your likely to have carbon build up in the intake valve. Petrol cleaner won't help as these engines are direct injection. ie fuel injected into the combustion chamber and does not see the back of the intake valve.

When I took my intake manifold on my 50k miles engine, it was quite choked up. I cam imagine yours will be alot worse given the millage. Also might be worth checking the diverter valve. If yours is revision d (rubber diaphragm) which tend to split and might give that feeling of lost of power.

Mine developed a hesitation occasionally which seemed to be cured by changing the fuel filter.

Might be a different symptom to yours but equally might be worth eliminating cheap options first.

Mine developed a hesitation occasionally which seemed to be cured by changing the fuel filter.

Might be a different symptom to yours but equally might be worth eliminating cheap options first.

 

Thanks.  I've just gone through my service booklet and it appears that the plugs have never been changed.  Is there any easy way to check otherwise?  I might just buy some for the sake of £30.

Just put a new set in the quite easy to do.

this sounds similar to mine, slight hesitation and stutter on gentle acceleration.

will look in to doing the sparks and coil pack.

 

I will also do some looking in to the intake valve and see what this does.

Just put a new set in the quite easy to do.

 

yeah done plugs a few times.  Do I need to gap them on the octy Vrs? Or will NGK irridiums be (ahem) 'plug' and play?

Edited 8 September, 201510 yr by planehazza

Go for the iridiums. They should be pre gapped

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sorry have not logged on in a while.Before I revisited this thread I decide to try cleaner again and filled the tank with bp ultimate. 

Car seems a lot better,only really have the problem when cold and gentle acceleration but no where near as bad as before.

When the car is now at optimum temperature there is no stutter.

I will check intake valve also.

I also used   NGK Iridium plugs and the R8 red coil packs.

Are these the right ones?

 

http://www.ebay.co.uk/itm/4-Pack-NEW-GENUINE-NGK-IRIDIUM-IX-SPARK-PLUGS-BKR7EIX-Stock-No-2667-Trade-Price-/350592387058?hash=item51a0ef47f2

I used awesome gti. code was BRKR8EIX.

I used awesome gti. code was BRKR8EIX.

 

 

Cheers.  Your code is slightly wrong, I think this is the correct code: BKR8EIX

 

£26.77 posted on eBay: http://www.ebay.co.uk/itm/4-Pack-NEW-GENUINE-NGK-IRIDIUM-IX-SPARK-PLUGS-BKR8EIX-Stock-No-2668-Trade-Price-/350592387185?hash=item51a0ef4871

Edited 8 September, 201510 yr by planehazza