problem spluttering at high revs

[nip]

hi all my cars being doing this for a while now on and off, problem is when u flat the accelerator at the end of the rev range it starts to splutter as if theres not enough fuel gettin in , also watchin the boost gauge it goes past 20 psi to approx 23 most when runnin normally it hits 20-21 psi any ideas chaps, btw theres always fuel in the tank

[Crawford_S2]

Doubt its fuel but could be, i would go for a set of plugs first, could be a missfire.

[UrS4boy]

nip: You didn't say whether your car is a 3B or ABY. Regardless, I suggest that you might want to read this:

http://forums.audiworld.com/s4s6/msgs/149788.phtml

Its geared to the AAN and ABY engines but there might be some things there to help you if you have a 3B.

Dave F.

[nip]

sorry s4boy its a aby,thanks for the advice, funny that a few weeks ago i took the plugs out and gently cleaned them then it ran fine again, but i did notice that the end of the coil packs on cylinder 1-2 the boots were ripped at the end the plugs look exactly as u explained light brown white tips.
i think im gonna buy some plugs tomorrow thanks matey

[twoqu]

Is the Ecu modified? If it's not, sounds like a lot of boost (@1.5-1.6bar) for a std car.
Possibly a boost leak. Need to check codes by blinking or Vagcom and/or get it pressure tested. Could be the overboost protection!

[nip]

no matey its modified just a homefries chip

[twoqu]

no matey its modified just a homefries chip

Hmm.. thats awfully close to the map sensor limit of 1.5bar(22psi). See above!

[nip]

just put new plugs in today seems ok for half aday them started misfiring again think this is the problem tho what do ya think

problem is its intermiten would this cause it

[pixsaudisex2]

so then nip i take it you got rid of this problem in the end what was it as it seems to be like mine is at the moment ...

[nip]

funny ya should mention that pix,after havin boost leak done, its back again, i think it can only be coil packs or boots gonna change them next

[PeteRR]

Certainly start by changing those coil boots first, they look rather past their sell-by date!

[Jamo]

Dem coil boots are well expensive on their own.

Considering the price of new coils and you get new boots with them consider buying new coils as well.

[nip]

the boots r about 20 quid each, was thinking of lending 1 good coil pack and changing each 1 to see where the problem is, will this b a good idea,??

[pixsaudisex2]

well i left the other day ( after rolling road ) on all five cylinders except for when you gave it some spuds got home looked at my coils id put on the other day and one looked mankey so i changed this for a new one i had ages ago ... id already changed the boots.. this made it much better ... then i thought hang on il chop out all the old wiring put new wires in and see now it goes then... three hours later the missfire is back again although not as often or as bad but its there and it wasnt before.... so im starting to cry .. now i am wondering if i should change the spark plugs but there ment to last for ever arnt they...

[pixsaudisex2]

and as for changing one coil at a time what a ballllllllllll ache ...