If, after installing an MSD Ignition Control, your tachometer, fuel pump relay or electronic fuel injection (in foreign vehicles) doesn’t operate correctly, your application may require a Tach Adapter. This is due to the trigger signal not being strong enough to trigger both the MSD and the factory’s components.There are a few Tach Adapters available and for more information see pages 152 and 153. Each Adapter is simple to wire in and will have your MSD and vehicle firing away in no time! If you are triggering an MSD Blaster, 5, 6, SCI, or 7 Series Ignition with its white wire or points terminal, you will need the PN 8910 Tach Adapter. The PN 8910 will correct the operation of most voltage-triggered tachometers or fuel injection systems that do not work directly off the tach output terminal of the MSD Ignition Unit.