05stangguy

Well, While I was driving along today, check engine light came on...oh great. Went to autozone had them pull the code, and it was a code stating that cylinder number 8 was missfiring. I was kind of dumbfounded, I have no symptoms, no lag, no NOTHIN. The guys at autozone all agreed it was most likely a spark plug issue. Has anyone ever had this problem? It's only one cylinder, which makes me think it's an isolated plug and not a coil issue. Could I be fouling out my plug from too rich of a tune? I don't think my tune is too right at all in all actuality, just trying to think of anything it could be...Thanks guys

Chris

Fresh_GT

Black_n_Blown has had this exact same problem with his (nearly) exact same setup. I don't think he ever really figured it out.

Were you in boost, or anything? Notice anything strange on you gauges?

05stangguy

nadda, nothing, NOTHING at all man. Hell my DAD was driving, and driving the car like a grandma to boot! Shifting around 2300 rpms etc. Not anywhere close to boost, just idling along. Everything seems completely fine, car has no signs of anything at all. Gets up and moves just like she always has

candymanjl

hummm, contact Kenne Bell about to get an ideas from them?

I know on Audi's / VW's the coil packs are notorious for going to crap and that'll cause miss fires. is that a common issue on mustangs?

05stangguy

Hey candyman, this was my next stop for sure, calling kenne bell. Also, VMP tuning is located about 20 minutes from my house, so I am going to give justin a call as well. Could this have anything to do with the OBD-II sensors etc? Possibly getting a bad batch of fuel or something? I read something in the manual that could possibly explain what I am experiencing, but I am not sure. But like I said, I have NO symptoms whatsoever, I would be surprised if the I am even getting any missfire, not to mention I am not sure how the supercharger could have anything to do with that?

candymanjl

bad fuel can cause misfires but it would run like *** in boost and you're saying that it's fine in boost.

there's honestly a ton of variables, good bet would be to hit up your local tuner and have him check it out. could be a bad plug, coil pack, injector, some sensor, all kinds of stuff. if your local tuner is any good he'll be able to diagnose it for you.

yzf29

I had a misfire on my on my F150 (with HO Whipple) and it turned out to be the coil on stick assembly. I got heavy handed removing it and ever so slightly cracked the electrical lead on top- if you looked at it- you never would have noticed it- I knew it- because I remember cracking it- but not thinking anything of it at the time- just put it out there FWIW

Good luck

05stangguy

thanks guys. Anyone have any other input?

BruceH

HT0's are good for about a year with a supercharger, Brisks about two months. Changing the plugs should be an annual maintaince thing along with the fuel filter when boosted.

Anyway my guess is you need new plugs. If it's been over a year change them no matter how they look.

05stangguy

Thanks BruceH, I appreciate your info. What spark plugs would you reccomend with a boosted application? I've heard 1 degree cooler is the way to go, but what about brands? what will a dealership usually charge to change out plugs and will they usually put in the heat signature/brand I want if I purchase them and bring them with me?