Misfires but the issue isnt the coilpack?

[redback]

Hey guys,

Since having my car GIAC'd for around 5 months, when id thrash it and reach redline, the check engine light would either flash then disappear after a few seconds, or it would stay lit. Right now it is the third time it has stayed lit. Every time i go to my mechanic the same fault shows up which the misfire in cylinder 3 and he also tells me that he was pretty sure it was the coil pack because he had the same issue with a few a3s.

So i took it to my VW dealer and got them to check it out and they saw the same code so they checked both coil pack and spark plugs and found they were all ok so they switched the cylinder 3 and cylinder 4 coils around and drove it around and said that they weren't sure if this fixed the issue but it did clear the code. They advised that they keep it over night so they could see what else they could find. But i declined because they might have eventually find out i retuned my car.

So i thought that was it with that but eventually the CEL popped its ugly head yet AGAIN! so i took it to my tuner and it was the SAME fault in cylinder 3 so he said it cant be the coil pack then. So he flashed me with a 'newish' GIAC program but the fault still came up. He said he talked with GIAC directly and they said it may be the fuel injectors.

Sorry for the long post, but could any of you guys help me out? not tryna start a whole you should have went with APR, Revo, blahblah war, just opinions/experiences because everything i've searched just showed misfires related to coilpacks.

Cheers big ears!

 

[CoNGLoMeRaTeGTi]

Does the car break up or back fire at high RPMs?

 

[redback]

not that i know of? the car still feels the same to me

 

[Deezz_Nuttz]

when they switched the coilpacks did they switch the spark plugs also?

 

[TimT]

if its constantly on the same cylinder then that would indicate some issue related to that cyl specifically. You already tried coilpack. Id switch spark plugs as mentioned above.. or perhaps consider an injector issue even?

what else could cause a cyl specific problem?

 

[TouringBubble]

Could be something as simple as the gap on the plug. Too much gap can cause misfires at high RPM.

 

[noszex]

I am having the same problem with my Pirelli GTI, that has been APR tuned. It at the dealer. I had a computer changed at my expense already because they said APR software was causing the misfire.??? So i have taken it to another dealer interstate and they are investigating the problem futher. Its either a injector or a valve issue which would mean major work.

i'm sure that there are other pirelli's around out there with the same problem

its always in 3rd gear at redline you get a cylinder 3 misfire!

just flash GIAC on pirelli few days ago, trying rev to redline on s. gt the blinking cel and gone after a while but car seem normal. check the code and clear it. not sure will it still happen again