Auxiliary output modes 7 and 8
Fuel Pump Relay Mode 7 The Fuel pump output is designed to drive a fuel pump relay. When the ignition is turned on, the output will energize for approx. 4 seconds and then turn off again. While the ECU detects that the engine is running it will keep the fuel pump on. If the engine stalls or stops, the Ecu will turn the fuel pump off after 4 seconds. This is a safety feature that is required in some motor sports.
Tacho Output Mode 8 When this mode is selected the output will produce a signal that is compatible with most tachos. In some cases where the tacho does not have an internal resistor connecting its input to power you will need to connect an external 500 – 1000 ohm resistor from the tacho input to power.
Stinger 4 instruction manual version 2.0