Timing / Misfire Help!!!

[grmair]

Apologies for posting this twice, i posted it in the maintenance section before in error...

Golf V GTI 05 Plate

I had this re-mapped with a SuperChips map back in March and all has been good until the last few weeks. It has a K&N high flow air filter and Denso Iridium plugs. Misfiring at high revs / alot of throttle led to the ignition coil on cylinder 1 failing this week. The replacement has brought the cylinder back to life but i'm back to having misfiring / timing problems with the throttle open again.  It may be that another coil pack is on it's way out but i'm pulling my hair out trying to work out what the problem might be.  I'm about to have the original map put back in the ECU to eliminate that, so if anyone knows something different before then i would be delighted to hear it...

Thanks to RedRobin for replying to my other post - I'll give that a try

[Cass]

VW/Audi coil packs were an issue some time ago (early 2000/2001 ish). If one failed, the others are likely to fail as they were all likely to have been manufactured in the same production batch.

You're probably right to revert to standard ECU settings in an attempt to resolve this - I'd go for replacement of all 4 coil packs.

Cass

[bacillus]

I agree re other coil pack(s) faulty.
Anyone near you with a vag-com to scan the car for DTCs?

[RedRobin]

....I'd use vagcom / check coilpacks before my suggestion of trying standard GTI plugs.

[brian g]

i'd try another coil pack as well as putting the standard plugs back in
i had problems only last year with a failed coil pack on my MK4
got a replacement from Europarts, got rid of the misfire but still had a vag-com open circuit problem
turned out the replacement coilpack was also faulty and I couldn't prove this until I got a genuine VW replacement

was a nightmare trying to return to Europarts too, took it back but didn't get the money back on my debit card until they had sent it away to get checked

[chungster]

Why don't you just give Superchips a call and see what they have to say?

I know when they first started remapping Mk5 GTI's they had problems with misfires but it was apparently resolved by using 1 grade colder plugs.

[grmair]

Many thanks to those that responded to this post.  After a few weeks and 2 failed visits to the main dealers, it turned out that the standard GTI plugs have sorted this out!   
FYI for whatever reason the non-standard plugs did degrade and eventually break the ignition coils. Although this looked like faulty coils, that was just the symptom of a different problem. 
Thanks again for your help, if i'd relied on the dealers instead of coming here for advice God knows how long it would have taken to sort out 

[RedRobin]

it turned out that the standard GTI plugs have sorted this out!   

....There you go - Just as I suggested. Glad it's sorted.

[vRStu]

I've run colder plugs in both my Octy's without issue.  It might be that your plugs needed replacing or setting properly.