Hi Jim!
Special message to you: When you define injection-duration in pure time, like mS (that is milliseconds, 1/1000 of a second) you know nothing about the total time available for injection. Don't you see? If a 4-cyl engine with sekvential injection runs at 4000rpm (66,6rps), you'll have a total time of 30mS available between each injection pulse. In other words, this sets a limit on the pulsewidth available. If you instead use the term duty-cycle at 4000rpm, you'll know exactly both the on time and off time of the injector. If at 4000rpm you have a duty-cycle of 95%, means injector on 28,5mS and off 1,5mS. So, don't tell me that duty-cycles isn't possible to use, it's far better than just using mS figures. End of lesson.
By the way, since I know Backyard Mech. are reading this aswell, I'd like to say: I believe I earn the same amount of money in an hour, as you do in a day. Have a nice day.