How can injector duty cycle be greater than 100%?
The injector duty cycle is a calculated PID and may display values greater than 100%. Values greater than 100% are “imaginary” duty cycles, the physical duty cycle of the injectors cannot be greater than 100%. When the calculated duty cycle is greater than 100%, the PCM is attempting to open the injectors for the next squirt of fuel before it has closed the injectors from the previous squirt. Physically that is not possible. Values above 100% are theoretical indications of how far out your injectors really are. EFILive calculates duty cycle for banks 1 and 2, using the following formulas: • {GM.IBPW1}*{SAE.RPM}/1200 • {GM.IBPW2}*{SAE.RPM}/1200 Technically speaking, the duty cycle is the percentage of time that the PCM is commanding the injectors open per 2 engine revolutions (4 stroke engine = 2 rpm per cycle). • At 50% duty cycle the PCM is commanding the injectors open for 1 revolution every 2 revolutions. • At 80% duty cycle the PCM is commanding the injectors open for 1.6 revolutio
