There are 5 different word phrases for fuel injector dead times. Fuel injector dead time, fuel injector load time, fuel injector lag time, fuel injector offset and fuel injector dwell time. These all have the same definition. Fuel injector dead time along with the other 4 definitions is the amount of time it takes the fuel injector to go from open to close. Voltage is what causes the Injectors to open/close, and depending on the amount of voltage, the injector can open faster or slower. Getting your injector dead times can improve idle and throttle response. This is considered fine tuning.