Trying to narrow down the problem! Help!
 

So I've got a 2006 6.0. Pretty much stock besides egr delete and sct livewire with looney tune on it. Recently, after the truck sits overnight, it cranks but either will take a long time to finally start, like its not getting fuel, and then run like crap until its up to operating temp. Sometimes it dies 1 second after starting, but starts right away the second time. Sounds like it has a bad miss, chugs, blueish smoke. No codes. FICM shows 48.5v on livewire. Good ICP. Shows 11.5 v on battery until glow plugs shut off then close to 14 v. Doesnt seem to have a tough time starting when the truck is parked on an incline, still runs like crap until up to operating temp.

Where should I start in diagnosis? Injectors gone bad?

Could be an injector issue....does it start ok when its hot?