seems I keep fouling plugs.
Searched and searched for a answer.
I have run Delco Iridiums
ngk tr55's (gapped at stock)
msd 8.5 super conductors, and msd blaster coil
I can swap in new plugs runs awesome for about 600-800 miles then it misfires.

Misfire, starts as light misfire on gentle tip in at low speeds in OD; just enough throttle to accelerate, but not down shift. Then it starts slowing down in high rpm's in 2nd (5500) Then it starts breaking up and miss-firing at 4500 under full throttle in 2nd . These are all progressions, starting from running great to running like crap. I run 93 octane, plus a bottle of 104 every second tank if I am able. These plugs are the third set in 5 months. I have a new cap and rotor also. Car has 148,000 runs very strong. Can it be
a) improper gap? .050 needed?
b) heat range?
c)weak valve springs (I have new lt4's and retainers waiting to go in regardless)
I don't mind doing the light work, but 500 miles in between plug maintenace is dumb.

 

could be a week coil bad module runnin rich due to coolant temp sens 02 sens .....what color r they when they come out

 

light greyish black. Coolant temp sensor is good. Brand new MSD coil. O2's are good too. UGH!!!!!!!!!

 

Swap the blaster coil with a GM unit.

I have had three buddies with LT1s have problems with the blaster coil.

 

done , same results.
Swapped plugs.
these were the NGK's 55, gapped at .05
main electrode light reddish, sides grey soot. I'll snap a pic of all of them. Looks like they were loaded up. Perhaps a heat range higher?

 

Is your fuel pressure regulator plugged into the vacuum source properly? Do you have a vacuum leak there?

Clean the MAF. I like carb cleaner. Anything but brake clean.

 

put factory a/c plugs back in it not platinums or anything see what it does