2008 Hemi revs up and down

[njohnson6425]

I'm kind of puzzled. When I start my truck the rpms will flex from about 600 up to 1500 and will keep doing that. sometimes it stops but for the most part it doesnt. When the truck is in drive or reverse it's ok and doesnt do that. Today I started it and it wanted to die but again when I put it in drive it's fine. It accelerates fine and shifts fine.. I dunno. I had it tuned in December and noticed it about a month after and also have the pedal commander. I haven't tried putting factory tune back on or removing the pedal commander. Other than these 2 things what would also cause these problems?

 

[Redtruck-VA]

That symptom is somewhat common to custom tunes. It's refered to as engine surging. Have your tuner look at your datalogs and adjust your tune.