Racing Fuel Systems

Installed the Grid system and now my autometer tach quits displaying the rpm's at 2400. I have a capacitor on the power leads between the battery power leads and the grid power leads. The only thing I can think of is I ran the coil positive [+] and coil negative [-] bundled in with the other leads i e the rpm wires, shift wires and all other leads going over to my terminal strip. Do you think I need to run the coil leads separate from all the other leads? I will try that tomorrow. Any other ideas? Thanks, Dave....