So I wondering about this. I removed my FCD which is not recomended anyway and was hoping by changing the setting to 0 to 30psi/5vdc FS would prevent my fuel cuts......but no, chilly day today and my car was fuel cutting like crazy.
My tune is great...just wish someone could tell how to prevent my car from fuel cutting.
I drove my car around the other day, went back to the stock supermap because the tunes I had worked on for hours for my summer tune and then again for my fall tune, included the exhaust mani leak I had, which is now fixed finally! but gotta start all over, either way whenever it drops temps it fuel cuts like crazzzy, it sucks.. but w/o the exhaust mani leak im hoping to tune that out, i hope 10-20 hours tuning should do it.
its pretty much a constant driving condition. Easy to avoid if I dont stomp it but still... I have my MAF relocated to the cold side and im pretty positive I have no leaks. My vac reads -20. I do have datalogging but I gotta admit thats one area of the ss afc Im not familiar with. I just got into adjusting the fuel maps. What should the MAF voltage be like 5 or something right?? And what part of the program would show me? Now that you said something bout the MAF I remember I did clean it with brake cleaner before I put my turbo in. Maybe I messed it up. My plugs and wires are new. And I find it hard to believe my coil packs would go bad right after installing my turbo. (I run a complete oem MSP kit with 40k and the addition of a fmic and ss afc) It just sucks to have a nasty tune but not really be able to enjoy it.
but anyways about your problem, I meant to quote your original question but anyways it sounds just like what happens to me sometimes, I would have thought it might be my exhaust leak because that was the only thing left that I hadn't fixed/checked, but the other day it still stuttered, did you say it lagged a little when you step on the gas hard? If so I have noticed that too, but I also see that if I look at the afr, they drop crazy rich as they switch over to open loop, I tried to drop my "over pressure" to 0 or .5, (I want to put it back down to -1 so it will switch over faster, like I had it before) but anyways that might be the reason why if when you step on the gas hard it happens, not sure how to get around that, maybe more tuning mightt help.. maybe, I know that when my brother had his 440cc injectors in it just lagged a TON, at least when he first stepped on the gas hard.
but also if you notice it lagging when you only do partial or 3/4 throttle, I notice that I do this a lot mainly because I don't really feel the need to put the stress on my engine every time I want some fun accelerating and boost lol.. at least not every time

, but anyways if it is at all cold or cool, or actually even when it isn't I noticed that the car or ecu almost fumbles between wanting to go into boost and not into boost, and if I don't push the gas pedal in enough it will kinda just sit on the line as if asking "what's it gonna be, you want to go or not, make up your damn mind".... this may all be in my head but I notice it time and time again, and the only thing I can think of is the ecu maps are just made like that, it is the msp, with that said, a good, and car specific tune will help that out a great deal, as will weather conditions,
I am sorry I don't really have a direct answer to your problem, but i personally believe that your might be experiencing msp quarks to some degree, and working on the tune (I've spent hours and hours screwing around with the tune, it's fun at least for the first couple hours, so than I just go home and do it again another day), a suggestion that might help is just record the temp out that day when you do your datalogging and tuning, and when it is cold or really hot, note that down, I would go for a temp that is in the middle of when you drive it the most, like I have a fall/early spring tune for when it's around 45(night)-65 out, and then a summer tune when it's from 60(night)-100 out, just make sure they are labeled on the tune.
so with all of that said, sorry for the long ass story, but I am just trying to say I don't think it is really any one thing (at least from what I can tell, and from my experience) but more just something that will become less noticeable with more engine power and more mods that decrease the stock control over the engine and it's power and the mods you put on.. just my 2cents, hope this helps a tiny bit