V50 Engine 2.0D : Occasional no turbo boost and limp mode

[zopo]

For about a week I had a problem with my Volvo V50 (2005, 2.0D). When i start the car, sometimes it starts normally, everything's working, normal turbo sounds and normal responsivity. Sometimes when I start there's limp mode light on dashboard which goes away shortly after but comes back from time to time and there's no boost. When I turn off and turn back on car sometimes it goes back to normal and sometimes it stays without boost. I read about 15 post regarding no boost pressure and limp mode but nothing solves my problem. Cleaned EGR valve few days back and everything seemed normal until today, when I was going to school and my car suddenly twitched and kept twitching for about 1 km when I stopped and restarted the car and everything was back to normal. I ran few diagnostics but only once there was a problem that came up with fuel pressure control valve, and I would like to know if that valve can be cause for this problems and if not what can be the culprit.

[Simmy]

you need to run diagnostics to narrow down your problem there are many possible causes too many to guess at and with diagnostics you will be able to check if your egr is working within operating parameters as cleaning is only part of the job

[zopo]

Now, it doesn't even want to start. It cranks but no start. I am afraid there's problem with high pressure pump, which is the worst case scenario.

[zopo]

Diagnostics showed that camshaft position sensor and fuel pressure control valve was out, so I bought a new ones. Will see if it solves my problems with starting and loss of power.