Hi. I've had an ongoing misfire/cutout issue for a while now and I've been told it could be because I'm using the wrong plugs, and i was hoping someone could confirm what plugs I should be running. Basically when I bought my IX it had a few usual bolt-ons (intake, manifold back exhaust, standard ebc) with my car remapped to 386bhp and not too long after I bought it I noticed sometimes it kind of misfires or cuts out for a split second when at WOT in 5th or 6th and then carries on as normal. It doesn't happen everytime but if I keep ripping through the gears it will happen. I've stuck in some fresh ilfr7h plugs gapped to the standard .5mm and recently fitted a COP kit thinking maybe the spark was struggling with the 27psi boost (according to torque app) but it's still no better. Someone has told me it could be because I need to upgrade my plugs but I just wanted some confirmation before I buy yet more spark plugs.

Any opinions appreciated

Thanks

 

you need to gap it down to .022 or so. with a 1/2 step colder than stock plug imo.

 

I'm guessing there's a bit of inches vs millimetre confusion here because .022" is actually .55mm which is basically what I'm running when you say colder would that mean move up to the 8 heat range rather than the 7?

 

Based on your power level and setup I would switch over to Denso Iridium IKH24 (5346) and gap them to .022" These are a step colder plugs that offer great all around performance when running high boost. I had the same issue that you are describing at around the same boost pressure until I switched over to these with a 0.022" gap.

-pal215

 

OK mate thanks. I just wanted to hear it from someone who wasn't trying to sell me the plugs lol I'll get some ordered

 

let us know how it goes!

 

Will do, thanks for the help

 

I run 34psi on ILFR7H with .022 gap making well over 500whp. I've said it time and time again over the years, you do not need a colder plug on the 9s. Every 9 local to me that I've tuned are also running over 500whp on the same plugs. All running factory ignition.

 

Hrm, good info there but not what I was hoping to hear obviously. I'm tempted to give the colder plugs a go anyway seeing as pal 235 said it cured a similar problem for him purely because I've got no other ideas, unless youve got some idea as to what it might be?