This could be the source of my misfire - failed plug wire

[Gumball]

Ya think?

My plug wires have straight ends and are really close to my 4-into-4 headers. I added insulating sleeves, but it appears that they were still a bit too close. This is the worst of three - the other two are very milky white and hard, with lots of cracks, but this one just disintegrated.

These wires were designed for an OEM appearance, but I'm now upgrading to some black silicone hi-temp wires with angled ends, which should route the wires up and away from the header primary tubes. And, just to be careful, I ordered a new set of insulator sleeves.

[Gordon Levy]

That would go a long way at causing a misfire.

[Svtfreak]

That would go a long way at causing a misfire.

Likely would go all the way there!

[Jeff Kleiner]

Uh, yeah, I think you found the problem!

Jeff

[j.miller]

Lightning under the hood, not good...da Bat

[avgjoe]

That'll do it! Even with wrapped headers and insulating plug booties and silicone wire ends they get replaced every year on the spec racer.

[CraigS]

Learned that 5 yrs or so ago. When i first got my MkII the original owner had installed some really nice wires. i saw that a few touched the headers but it hadn't affected the silicone at all. Took 3 more years until I had a light miss. Played w/ carb jetting for a while and then saw the same thing you have. That silicone is fantastic but it isn't forever. I got Summit house brand wires w/ 45 degree ends.