Please see the video above, I don't have a fuel pressure meter and I think this problem may be pump related. First part of the video is the sound from the pump, and the second part is me trying to hold the engine at 3-4000 rpms. I can't hold higher rpms, and it surges as well when driving but only in light traffic and not when you are on the gas. Also stumbles a bit on initial startup in the morning. Am I on the right track here?

 

i had a similar problem on an earlier volvo (760gle) turned out to be a dirty throttle body

 

Throttle body was cleaned, two coil packs , water pump, timing belt and plugs