there is a post in forced induction about injectors and someone posted this link http://www.supras.com/~riemer/sonict...rs/RCtech.html

something very interesting to consider when sizing injectors that i didn't know is that you never want to go over 85% duty cycle. i always just thought it was kind of hard on the injector but thats not it at all, the flow rate may actualy go down when the injector starts to go static right before it goes full static.

here is part of that article.


Most pintle type injectors fail at 86%/88% and the Disc will usually go to 92% +, depending on system pressure. All must cycle smoothly up to 85% to Pass. Bad injectors will sometimes go "static" at 70% or so and are discarded. NOTE: Most pintle injectors will increase flow rates up to 88%, 92% with Disc injectors, and then go "semi-static", half open-half closed, just before going full static. This time-out event occurs at different time/pulse width durations, in different injectors, but always produces a 50% or so Duty Cycle flow rate. This extremely dangerous situation will usually occur at the worst of times, full throttle-max boost-high RPM- just when you need 100% fuel delivery you get 50% and go dead lean. BANG!!! This problem seems to amplify a bit at higher pressures.



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