hello i need some help with vivaro 1.9 tcdi 2006
problem began when ran out of diesel

fitted new filter and bled system and now its a real pain in the ass to start ..........when it does eventally start it has no power !!! put foot to flow and it takes long time to go from 1000rpm to 2000rmp then it just stays there for about 1 minute then it revs up ok and drives perfect !!!!!!!!!! turn it off and it starts and drives ok !!!!!!!!!!!...........leave it till end of day then same problem .......i have no fault codes either and if i spray easy start in filter it starts straight away but still has the flat spot between 1000 rpm and 2000rpm !!!
things i have tried and changed are

new fuel filter
new boost pressure sensor
cleaned erg valve
cleaned fuel lines from the hand pump to tank
fitted new glow plugs
blew air slowly through line to pump in tank with fuel cap off and you can hear it bubble
bled system 3 times
no air bubbles

still same problem this morning ............it turns over starts and direct stops ........if i spray in easy start it starts and runs but no power like i mentioned above ..........
maybe someone knows the issue with this .....could really need some help ....big thx in advance