Surging under load and very slow boosting
 

Hi my 08 cummins. 112k fully deleted efi live. While under load. It surges almost like its starving for full. Rail pressure at full throttle is around 22k. The other day I noticed my boost was extremely slow to build. When this started the lightning bolt on dash started coming on ramdomly. It's chargeing around 14v. I have cleaned the terminals and such. I was almost thinking possible bad lift pump starving the injection pump. ? Plan on hooking up gauge this week. Forgot to mention this is the truck in my sig. And only code if throws is. P2580 which is a turbo Code. But it's not a stock turbo anymore and has ran like this for a long time