LMM: high pitch dieseling sound after 2500 rpm

[cdbright]

Once i hit 2500 rpm it sounds like a high pitch "dieseling" sound,it sounds like it is de-fueling , i change the fuel filter every time i change oil and it has only been about 4K miles, and i do NOT get a change fuel filter warning yet, does it on all tunes so it has to be fuel related right, if i lay on it there is still plenty of fuel to pull and it will go well past 3K RPMs so there has to be enough fuel for it to do that right?

I know have about 108K miles and it seems to just start doing it lately. Cant be a engine finally getting broke it right?????????????????????????

 

[cdbright]

also cant read fuel pressure on my gauge cause the damn LMM does not like when you pull a signal of the wires for it, tried 3 different gauges and it makes the truck knock as soon as you hook it up

 

[cdbright]

Any insight?

 

[PureHybrid]

Under what load conditions? Free rev, driving, towing?

Could be pilot injection shutting off, fuel pressure ramping up. But doesn't make sense if the problem just occured. Take a video if you get a chance.

 

[WolfLMM]

Get a log of the fuel pressure. Actual vs desired. That will help us out as well.

 

[Harbin_22]

If it has always done it since tuned, it probably is pilot injection shutting off. Little low on RPM for street driven truck of that's what it is. I like to leave pilot on until 2800

 

[cdbright]

it seems like the tune was written that way so it lets off a little to let the next gear slip in. I never seemed to notice it before but maybe now i do cause i worry about it, i will make a video today , i dont have a logger to monitor fuel rail pressure and my guage will not work on my LMM , cant seem to find one that does not make her knock when sensor is tapped into harness

 

[bmc1025]

Like said above it is most likely tuned to shut off the pilot injection above 2500. Nothing wrong with tuning that way but does make for a noisy street truck especially when towing heavy.