I put a new cap and rotor on my car about 2 or 3 months ago....and now it has sparks coming out from underneath it at random times and places. One idea has crossed my mind but I don't know if it would work. I thought about getting a hi-temp peice of plastic and cutting it to fit under the rotor and make it as big around as I could....so the spark would'nt have no choice but to go up ........would this work or do you guys have any better idea's

Thanks guys,

I drag 2

 

I don't think the plastic will work. Once the spark travels down the inside of the cap it leaves a carbon trail (called carbon tracking I believe). It should look like a thin black line. This trail makes it easier for the next spark to follow the trail, then the next and so on.
Sometimes it will travel to another plug wire terminal.
Moisture inside the cap is probably what allowed the first spark to wander off the intended path.
I've tried to clean off the carbon track before, but had no luck. It's fused into the plastic.
I'd just replace the cap and see what happens.

 

Get a new GRP cap with brass terminals and deep arc chutes. You'll find these features in many brands, so the name really doesn't matter.