I went outside tonight and started up my truck beacuse I had a suspicion that one of my wires was grounding out beacuse the engine would idle rough and lack power at low speeds and miss. Sure enough I have a little light show coming from cylinders 1 and 6. The engine was rebuilt about 400 miles ago and the wires are brand new. I have spark plug heat sheild sleeves around all the spark plug boots beacuse I have downey headders. Would this cause the wires to ground out?