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Injector duty cycle % when to go bigger?

hellno

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#1
I am curious as to what injector duty cycle percentage tells you need bigger injectors ex: 70,80,90 %
Also let’s base this on a issue free vehicle that is running properly
 


ostmike

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#2
The typical response will be 80% duty cycle. Just keep in mind this platform has a variable pressure fuel pump so you should also monitor fuel pump duty cycle. If the pump duty cycle is at 100% and your injectors are at 90% and your WOT fueling is not too rich then it is time to consider fuel system upgrades (injectors and/or fuel pumps).
 


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hellno

hellno

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Thread Starter #3
The typical response will be 80% duty cycle. Just keep in mind this platform has a variable pressure fuel pump so you should also monitor fuel pump duty cycle. If the pump duty cycle is at 100% and your injectors are at 90% and your WOT fueling is not too rich then it is time to consider fuel system upgrades (injectors and/or fuel pumps).
thanks for the reply mike ,its good to see a actual tuner chime in I do agree that 80 percent is the I guess you say point of decision time but in my case I have logs showing fuel pressure, and duty cycle to be fine but idc going as high as 88 I now added a jms bap and the the most I ever see now is 83 but only at like redline 6300-6500 fuel isn't too rich or lean and fuel pressure now reads min 89-92 psi and fuel pump duty cycle never goes over 73% ,funny thing is I called the other day and micah mentioned 80 being the high point ,mines tuned by curt( which im very satisfied great tuner in my opinion ) and I couldn't sleep so I was curious to what the opinions were
and my question to micah was actually about a totally different subject ,that had nothing to do with tuning it was about the stage two package and the fuel yall ran at the track when it first saw 9.8 1/4 times
 


FFBOS

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#4
I always look at fuel pressure (when things are working right) and duty cycle.

If fuel pressure drops over time, the pump or pumps are probably getting tired. You’ll also see the duty cycle climb because of that.

On my old Trinity I would set the alarm on it to 70% so I would know if anyone of the 8 injectors ever saw that. My new Trinity needs some work to get these features back. Having immediate “heads up” is always nice.
 


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hellno

hellno

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Thread Starter #5
I know first hand how pump effects injectors duty cycle
 




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