Ground for the coil?

I have an intermintent ground problem, sometime when I hit a ruff bump in the road, it makes my truck run like shit! Yeah, motor cuts out, but doesnt die,and chugs and hesitates really bad, I had a similar problem on my toyota and it turned out to be a loose ground on the ignition coil, so where is the ignition coil on a 1996 nissan hardbody?