95 Rodeo Missing/cricket Noise??

I bought a 95 rodeo today v6,and its missing mostly in drive and especially between 45 and 50 mph.It does miss a bit in P. I came home and I opened the hood and being that it was dark I saw arching one the plug wires on the right side guess there split or something. Also When I accelerate I here what sounds like a cricket under the hood.CAN SOMEONE TELL ME WHAT THIS IS??