An arduino program I made to test fuel injectors
I used an arduino connected to a MOFSET to switch an adjustable-voltage signal to the injector, it seemed to work well to test the injector dead times, etc.
You can adjust the first five variable to simulate different engine situations:
// enter two of the three variables bellow. If all three are entered, only pulse and duty cycle will be used.
float pulse = 2.35; // pulse width in miliseconds
int RPM = 0; // RPM of smulation
float dutyCycle = 50; // duty cycle of injector
int continuous = 0; // if 1, injector will fire continuously
// enter the duration of test run
long duration = 2.5; // total running time in seconds