Help please think I need new coil pack but not sure which one

[audiv8quattro]

Hi all my car has been running like s**t lately, really lumpy and juddering, the juddering is intermittent though, so I checked the coil pack and it's got good spark from numbers 1,3,6 and 5 but 2 and 4 is only sparking a little, not as much as the others, so my question is
1. Would this cause the car to run like it is and
2. The part no I have is 078 905 101c, does it matter if the part I buy has an A at the end instead of a c,
The cars a 2.6 v6 quattro on a p plate. Thanks for any replies

 

[aragorn]

I think the 2.6 has 3 coils, running wasted spark, so if one failed it would make sense that two cylinders would have a weak spark.

Theres a "C" part on ebay.

 

[audiv8quattro]

Ok thanks aragorn so I take it the "c" part would fit it doesn't matter that mine has an "a" at the end

 

[audiv8quattro]

Sorry just realised what I wrote, that's the exact part I'm looking for mines a "c" not an "a" it been a long day.

 

[NineNails]

Try swapping the coil to see if the fault moves cylinders, then you know you deffo need one

 

[audiv8quattro]

Cheers ninenails but I ordered the coil pack from eBay anyways managed to get one for 20 quid so not to sad I just hope it's the coil pack that's at fault

 

[audiv8quattro]

Ok so coil pack came today while I was at Work so just got home and fitted it, was abit fiddly but got there in the end and it seems to have made a difference, only took it round the block so will let everyone know how it drives tomorrow, thanks for your help everyone

 

[NineNails]

Hope it's all sorted pal

 

[audiv8quattro]

Cheers ninenails so do I, I'll let you know tomorrow