stealth_GT

Wow.. I had a bad misfire for about a week and only now have I been really able to pin point the problem. I kept getting the P0308 code for about a week or so and haven't had any time to diagnose it any further..

I went through basic text book stuff (vacuum hoses, boots, plugs, gap etc.) and I pulled the plug and swapped it with it's companion cylinder..

it ended up spitting a P0304 code. Spark plugs, has to be it. So I inspect it again.. looks normal, nothing out of the ordinary.. until a senior tech told me to remove it from the spark plug tool..

BAM! loose terminal nut! I wouldn't have even noticed it if it wasn't for him advising me to! Basic knowledge tells you to check the gap, check for carbon build up, abnormal wear etc. and you assume the terminal nut is in place..

not with the Brisk Racing one step colder plugs. I have been having problems with them all week! I thought they went bad (for no reason?!), but luckily I caught the problem!

If you guys are running those spark plugs, I highly advise that you check the damn terminal nuts and make sure they are SNUG! Tighten them with a set of pliers, clean the porcelain! Use a TINY bit of lock tight if you have to!

That damn plug has given me a headache all week! When I inspected it, it was so loose it could have spun off with little effort.. yeah, that's not conducting the correct amount of spark rofl

tx_zstang

Good find, good lesson learned.

stealth_GT

Thanks.. it's the little things that get ya in trouble! lulz

When I compared the spark plugs, 4 and 8, I must have inspected the no.4 terminal nut and it was snug, I assumed it was a one piece and did not inspect the no.8 (initially).

Car runs like a champ, though one step colder isn't the best especially for daily driving/NA and around town...

Riptide

I've seen this before with a set of brisks. Not exactly encouraging to hear someone else finding the same issue in another set. And we paid $18/plug for these things? Pathetic.

stealth_GT

sorry, must have worded it wrong... I did mean the Brisk racing plugs..

I meant, you assume the terminal nut is a one piece.. not with the Brisk racing plugs (it's two piece lol)

It's all good, lesson learned and it's a simple fix, unless of course it comes all the way off and gets stuck in the coil in the boot rofl now THAT would be very annoying!

stealth_GT

Yikes... Been having bad idle issues again and check engine light coming on daily.
I ended up pulling all the plugs... ALL of the terminal nuts were loose!

Not only That but one of the plugs, the terminal nut and the electrode separated from the porcelain while another was starting to separate!

Luckily, I have two extra new ones just in case. Oddly, a few of the spark plugs also were mis gapped at 0.40 while some were at 0.38..

This explains so friggin' much!!
I knew something was up because it wad just not idling right and I kept on getting the p0300 code (random misfire).

I cleaned them off, re-gapped at 0.35, tightened up all the terminal nuts and re-installed them...

Woah! Silky smooth idle at last and the throttle response is so much better.

Parked idle improved greatly but still has a slight burple here and there but nothing bad like before..

Amazing what a little elbow grease can do lol

Simon1

I replace my plugs twice a year with FI, generally. 16psi, lots of timing and racing equates to a hard life on the plugs. I still use the HTOs and have only had one or two give me problems.

I also keep a brand new set handy in my race bag when I go to the track. Gapped, anti-siezed and a tube of di-electric grease with them.

Chasing electrical problems is the worst ever!

Simon1

When I do my plugs I pull them out, let them cool, then inspect them thuroghly when I can handle them with my fingers. Checking for tea colored stains in the porcelain, hot spots on the electrode, cracks (anywhere), I shake it to listen for anything, then I clean it, anti sieze it, check the gap and put her in.

Riptide

Unacceptable to see this with an $18 plug.

contentsunderpressur

Your problem was the gap, not the nuts being loose. There is enough power coming from the coils to jump a 1 1/2 inch gap so loose nuts wouldn't mess with the firing. A supercharged car will start blowing the spark out and missing when the gap hits .040. I always ran mine at .032.