Bought my first Dmax and need a little help plz...

Hi all, I bought a 2008 2500hd and it has been great for the first couple of weeks. But I've had a few *reduced engine power* issues pop up now. Two of the times were under heavy acceleration and the other was hwy with the cruise set at 78ish on fairly flat ground. It did it twice with the tune that was in the truck when bought and once since I loaded a tune in that I used a stock file to compare and go back to a mostly stock tune. *as long as what I found in the repository was stock.

Each time I've gotten the code p0087-Fuel Rail/System Pressure - Too Low

I was hoping that the tune that was in the truck was just a little too hot and that making the changes to make it mostly stock would alleviate the issue but I'm not so lucky. Hoping someone would look over the tunes and see if anything stands out, as of now the majority of my tuning has been on gas lsx vehicles. I will attempt to add the files now, never uploaded one here so hope it works lol...

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Haven't got my tuning laptop handy, but in one the other posts i posted my 2010 LMM stock tune file if want to compare. Believe it is stock as no mods to the truck physically. How many miles? From what I've read depending on miles, and how clean fuel is, CP3's can go bad since our trucks don't have a lift pump. Its possible even with a stock tune if you're commanding heavy FRP and its not seeing it, it'll throw the code. Have you logged it at all? From what i've read you'll see the large variation from cmd frp and actual. Actual can be sporadic. (again this is just what i've read, i've never had one go out on me). Actually, could be FPR as well now that i think of it. Fuel Pressure Regulators go as well sometimes. (ready alot on this last year when diagnosing a problem with my LB7).
Also theoretically a stock tune over a 'hot' tune should help the CP3 keep up as its not letting as much fuel go so quick when you are heavy on the pedal. Sporadic actual Fuel Pressure may indicate the FRP as well.

Thanks for the reply, truck has 287k miles so its higher but hoping still in good shape. "I'm the 4th owner and its super clean for the year and mileage"

I'm setting up my scanner now to log fuel rail pressure and commanded fuel rail pressure, would there be much else to log as far as fueling?

For diagnosing your pump this will suffice. If wanted to go further if trying to tune you could log your injector fueling. But for what you are after you should be good with just actual and commanded pressure.

So I logged fuel pressures and on the "big end" rail pressure does tapper off from desired pressure *around 4-6k*. But now I've been running a 10/10 tune I guess, I added 10% to fuel and boost then used the timing calc @ 50% for my current tune and the truck hasn't limped unloaded.

And to be honest thinking back when it did limp with the tune that was in the truck when purchased it wasn't while in the throttle but a few moments after letting off of the go pedal. Not sure if that makes any difference. With the current tune I do get a random "surge" as if the truck drops a little power for a second then comes back, when loaded with car on trailer it is more noticeable but doesn't limp unless I get on it then let off.