DIS-2/DIS4 TACH ADAPTOR Wire your tach correctly.
Dual ignition tach adapter
This dual ignition tach adapter is designed for vehicles using MSD DIS ignition controls. It has two channels, for two coil pack applications. In some applications, when you add an MSD ignition, the factory ECU no longer can tell when the coil has fired, which is what tells the ECU to fire the injectors or tachometer. This adapter simulates the coil signal, thus allowing the ECU to properly trigger both the tach and fuel injection with the MSD DIS ignition. In most cases, the adapter plugs directly into the MSD harness.
Sold individually.