142 How Big Does a Fuel System Need To Be

Hi as I watched the recorded version of this webinar a question came to my mind: On my Haltech platinum 1000 I've see'n injector duty cycle exceed a 100%, how is this possible?

I mean what is the purpose of the injector duty cycle display when 100% isn't maximum, how are you suposed to know when yot are starting to run out of injector?

If I remember correctly I had injector duty cycle at 130% when I in theory should be no way near of running out of injector or fuel. (1000cc injector, walbro 255 at 45,3psi base fuel pressure and 14-15psi of boost on a 4 cyl piston engine)

Technically you can't exceed 100% IDC as the injector is simply open for the complete engine cycle. I've used several ECUs that will report a larger IDC but that is just the result of the fuel calculation - It's not real and the actual IDC will just be 100%.

Have you tried measuring fuel pressure during a sweep pull?

If your commanding 'over 100% duty' at only 14-15psi you've either got a massive turbo or a fuel supply issue