Good day,
I'm having trouble finding information about whether or not the HPFP learns, or have trimming it tries to accomplish (I'm a stock LT4 long block, with a Maggie 2650, and port injection, for the most part, running E85, FWIW). I'm seeing conflicting SCANNER data between 2-files that are, effectively, the same, but am showing different DESIRED HIGH PRESSURE fuel request, and results in differing actual FUEL PRESSURE, even in the exact same cells (MAF/DESIRED RAIL PRESSURE). Does the HPFP have learning, or trimming, or is it something else? I'm having trouble posting files, but can see if I can figure it out if anyone has ideas that need them. I'm more embarrassed of anyone flaming me over my tune, lol...
I have a couple files, with, essentially, the same tuning, but see that the HPFP PRESSURE (desired AND actual) are different in each scan, even though I'm in the same cell of the MAF curve, about the same RPM, and at the same CYLINDER AIRMASS. ACCELERATOR PEDAL/THROTTLE are also the same for each file. I'm only seeing COMMANDED RAIL PRESSURE (and actual rail pressure) in one of these scans, and seeing a different COMMANDED PRESSURE (and actual pressure) in the other, even though, everything, above, is the same. This is resulting in my STFT/LTFT trims going wildly LEAN or RICH. One these runs, one was LEAN, but the other was RICH, even though the tunes were, effectively, the same. Dynamic AF (and MAF/VVE are also within a few percent error) shows that I'm within a few percent of each scan at this, same, point, so I feel like I should be in the same AIRMASS cell of the DESIRED FP table, which it shows I am, in both scans.
Is there a learn or a trim the ECM is performing for the HPFP? Why would I see different values, with, essentially, the same files? Maybe it’s helpful to add that I am trying to integrate port injection, in conjunction to the E92. I am trying to make the fueling compensation with [33355] adjustment, by trimming fuel in what would be higher fuel pressures in that profile (< 16MPa are about 30% higher than stock). I’ve be trimming fuel, in that profile [33355] by over-reporting fuel flow (in that multiplier), and it works just fine from about the middle of the E92 MAF curve to the WOT-end of the curve. I’m seeing DESIRED FUEL PRESSURE wander around the middle of the MAF CURVE, though, right around the transition from PROFILE 2 to PROFILE 3 (so - from around 14-16MPa). I DO know I have a relatively large leap in requested pressure in this area, and think this COULD be the issue, but was wondering if anyone else had this experience, too. This doesn’t seem to be a popular method of supplemental fueling control, or, my Google-fu is just that poor, or this method is just not shared much. I thought I’d ask anyways.
Thank you,
Chuck
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