Chris.b_85t
Member
Anyone have an offset value for Afis 120lb? Any help would be appreciated. Thanks
Afis injector dead time
- Thread starter Chris.b_85t
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Chris.b_85t
Member
They are a low impedance. Part # 8771208
Chris.b_85t
Member
Thanks for the info. Excellent help as always.
there are a couple things.
if your VE is much different than 45-50 at idle, your deadtime may need adjusting
there is also a test mode you can use to switch between sequential and batch. if the fueling changes much (either AFR or the ECO correction) then the deadtime likely needs adjusting.
But, if the car runs well, there may not be a compelling reason to mess with it. (in my case, its 'close enough' and the car runs great)
Bob
if your VE is much different than 45-50 at idle, your deadtime may need adjusting
there is also a test mode you can use to switch between sequential and batch. if the fueling changes much (either AFR or the ECO correction) then the deadtime likely needs adjusting.
But, if the car runs well, there may not be a compelling reason to mess with it. (in my case, its 'close enough' and the car runs great)
Bob
Thanks Bob.
But really the deadtime only applies at idle, is that right? Part Throttle and WOT are still tuned mainly with the VE table?
Would the tuning method for deadtime be something like:
1. Set VE in the idle ranges in the VE table to be 45-50
2. Choose a dead time as a starting point, maybe .75ms?
3. adjust deadtime up or down until correction goes to 0 (or displays 100%)
When will the curve need to be adjusted? Is the curve shape more an adjustment to compensate for the voltage behavior profile?
Mike
But really the deadtime only applies at idle, is that right? Part Throttle and WOT are still tuned mainly with the VE table?
Would the tuning method for deadtime be something like:
1. Set VE in the idle ranges in the VE table to be 45-50
2. Choose a dead time as a starting point, maybe .75ms?
3. adjust deadtime up or down until correction goes to 0 (or displays 100%)
When will the curve need to be adjusted? Is the curve shape more an adjustment to compensate for the voltage behavior profile?
Mike
It's added to injector pulsewidth always. As a percentage, it has most effect at idle (low pulsewidth). However, if you have a very large injector (like 120's and up), that operates at low pulsewidths much of the time, then it can be significant when cruising around.
Your method of tuning will work. However, I typically have the deadtime, voltage compensation, and low pw table (if used) set up pretty close.
Your method of tuning will work. However, I typically have the deadtime, voltage compensation, and low pw table (if used) set up pretty close.
Thanks Eric. my question was more for my understanding (and anyone else that is reading this) in the case where it was initially setup for say 60lbs/hr injectors but then move to 120s or even 160's.
I assume that the parameters you describe will be injector dependent? Can it sort of be estimated from injector data (if available) or is it more trial-and-error?
Mike
I assume that the parameters you describe will be injector dependent? Can it sort of be estimated from injector data (if available) or is it more trial-and-error?
Mike
The injector flow rate, deadtime (includes voltage comp.), and low pulsewidth info is all injector specific. So if you change injectors and update all these things, there will be (theoretically) no tuning changes needed.
Many times this info can be provided by the injector manufacturer, sometimes you start with something close and fine tune it. The best way is to flow-test the injector with the proper hardware to measure all this info.
errors in these settings can be 'tuned around', and the car will run fine. But it makes the tune more sensitive to swapping injectors...
Bob
Many times this info can be provided by the injector manufacturer, sometimes you start with something close and fine tune it. The best way is to flow-test the injector with the proper hardware to measure all this info.
errors in these settings can be 'tuned around', and the car will run fine. But it makes the tune more sensitive to swapping injectors...
Bob