how to correct going rich on decel
09-23-2013, 09:28 PM
#11
What is your pulse width when this is happening? There is a set min pulse width that needs to be lowered if you are hitting it. I can get my 160lb injectors to sit at 14.7 AFR under hard decel at 1.11ms on gas. EFI Live unfortunately does not offer this adjustment, but luckily in your case HPT does. The table is under transient, and the very top left area is minimum fuel milligrams. With larger injectors you often would need to lower this. In order for this to work for me I had to change a stock tune with HPT, flash it in the truck, take it off the truck with EFI Live, then make my adjustments to everything else in EFI Live.
09-23-2013, 10:05 PM
#14
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i wouldnt really be concerned about it on flat land.. but i drive through the mountains some times and it sucks seeing the wideband stay at 11.0 for long periods of time.
09-23-2013, 10:17 PM
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I was confused about the default and minimum pulse width tables when i was entering the injector data, it was kind of vague how it was explained. fixed now. and i don't think i'm hitting the minimum pulse width, the table is set to .125 ms all across and the lowest i've seen my logged pulsewidth go is 1.8ms. how would i adjust the minimum fuel milligrams value? just cut it in half?
Last edited by MechE; 09-23-2013 at 10:24 PM.
09-24-2013, 12:41 AM
#18
I have FIC 60# injectors (72# at 58psi), and their data is incorrect from what I can tell. Apparently they take their data from Injector Dynamics and reswizzle it slightly. I had the same issue and had to change the injector data to get low enough pulsewidths. I had to lower the offset table quite a bit (around 20% IIRC( and drop the min transient pulsewidth (raise your entire VE table if you lower the offset table or else you will be lean). Now I can get down to 1.3-1.4ms on decel and it doesn't go rich. Of course this means that the VE table may not be accurate, but for tuning purposes it doesn't really matter. Having the correct injector data is essential.
DFCO isn't as effective anymore with big injectors as mentioned, but it still activates and provides engine braking. I'm considering going to smaller injectors, so far I've only gotten up to around 60% duty cycle on these.
DFCO isn't as effective anymore with big injectors as mentioned, but it still activates and provides engine braking. I'm considering going to smaller injectors, so far I've only gotten up to around 60% duty cycle on these.
09-24-2013, 06:47 AM
#19
EFI Live only made this available in the CAX file as B9021. HPT has this available as the minimum fuel milligrams. I did not discover this, I was directed down this path by a fellow PT user that deserves the credit. I just decided to spend the credits on HPT to try to change it and it worked. I love EFI Live, dont get me wrong. I love the COS, but EFI Live needs to understand that there are plenty of people using their software on the 02-07 OS's, and they need to address this issue.
09-24-2013, 08:10 AM
#20
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This ^^^
That is the "ceiling" for minimum pulsewidth. Wouldn't matter how low a number was in the tune for minimum pulsewidth it will still be trumped by the table mentioned above. It's under transient fueling tab. Take the number and cut it in half for starters.
Do you have all of the fuel injector data set right in the tune? Voltage offsets, SPA (short pulse adder) etc....
With the correct injector data and an adjustment made to this table I have tuned many setups with 60-80 lb/hr injectors which I have gotten a good clean idle and decel.
Last edited by 03klugss; 09-24-2013 at 08:41 AM.