So I have had my turbo on my truck for a couple months now probably. I already went through the issues trying to run speed density, and then I decided to go back to MAF and I put a LS7 style MAF in the charge tube right before the throttle body.
I also upgraded the stock L9H injectors to FIC 850CC ones a week or two ago and seemed to be no issues. Lately I have been trying to get the MAF dialed in better, but, similar to VE/VVE tuning, it seems like I get nowhere, and the moment you think you are getting somewhere, then the next log file you get double the error you go back to the error you started with.
So the first thing I noticed was trying to do a boosted launch it felt like it had no power until second gear, so the logs were showing the EQ from the wideband slowly diverging and leaning out until second gear. So I started trying to mess with the MAF curve again with no luck. Now today randomly I am getting extreme lean out under half to full throttle but its completely random when it will be normal and when it will lean out. It seems to more consistently do it when I roll into about half or so throttle, but its done it to just going WOT all of the sudden.
You can see in this log the weirdness. To me discontinuities should never exist in logged data, or in calibration files for that matter as well, but circled in red you can see the boost curve ramping up and then the air mass per cylinder seems to diverge from it. It doesn't rise with the manifold pressure (boost) increase, then all of the sudden it does with a sharp discontinuity. You can also see below in light green the wideband showing it leaning out.
Capture.JPG
So I am back to full stock with a functioning MAF, so I don't' think I can blame the famous E38 speed density issues and weirdness. I am just baffled that the ECM is just blatently ignoring airmass and just deciding it doesn't want to fuel appropriately and disregard increasing airmass.
Does anyone have any ideas?
White Truck Turbo ECM TCM FICM.hptWhite Truck Turbo Log 18 More Random Lean Events.hpl